Firmware and User Manual Updates. Dear Customer,. In an effort to keep the
1918-C Optical Meter optimized for your applications, Newport will on occasion ...
Model 1918-C Hand-held Optical Meter
User’s Manual
ii
Preface
iii
Preface
EU Declaration of Conformity We declare that the accompanying product, identified with the mark, complies with requirements of the Electromagnetic Compatibility Directive, 2004/108/EC and the Low Voltage Directive 73/23/EEC. Model Number: 1918-C Year
mark affixed: 2007
Type of Equipment: Electrical equipment for measurement, control and laboratory use. Manufacturer: Newport Corporation 1791 Deere Avenue Irvine, California 92606 Standards Applied: Compliance was demonstrated to the following standards to the extent applicable: BS EN61326-1: 1997+A1+A2 +A3 “Electrical equipment for measurement, control and laboratory use – EMC requirements” Performance criteria B was achieved during immunity tests. This equipment meets the CISPR 11:2006+A2 Class A Group 1 radiated and conducted emission limits. BS EN 61000-3-2:2001, Harmonic current emissions, Class A BS EN 61000-3-3:2002, Voltage fluctuations and flicker BS EN 61010-1:2001, 2nd Edition “Safety requirements for electrical equipment for measurement, control and laboratory use”
Bruno Rety Group Director PPT Instrument and Motion Europe Zone Industrielle 45340 Beaune-la-Rolande, France
Dan Dunahay Director of Quality Systems 1791 Deere Avenue Irvine, Ca. USA
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Preface
Firmware and User Manual Updates
Dear Customer, In an effort to keep the 1918-C Optical Meter optimized for your applications, Newport will on occasion update existing, and add new features to this instrument. To utilize this new functionality will require an update to the instrument's firmware, which can be easily accomplished by the user, as described in this User Manual. As required, Newport will also generate a new version of this User Manual, reflecting updates to the instrument. Please check the Newport website (www.Newport.com) for newer versions of the firmware and the User Manual, which can be downloaded as a PDF file. Call your local Newport application specialist if you need support with locating or downloading these files. Enjoy your new instrument!
v
Preface
Warranty Newport Corporation warrants that this product will be free from defects in material and workmanship and will comply with Newport’s published specifications at the time of sale for a period of one year from date of shipment. If found to be defective during the warranty period, the product will either be repaired or replaced at Newport's option. To exercise this warranty, write or call your local Newport office or representative, or contact Newport headquarters in Irvine, California. You will be given prompt assistance and return instructions. Send the product, freight prepaid, to the indicated service facility. Repairs will be made and the instrument returned freight prepaid. Repaired products are warranted for the remainder of the original warranty period or 90 days, whichever first occurs. Limitation of Warranty The above warranties do not apply to products which have been repaired or modified without Newport’s written approval, or products subjected to unusual physical, thermal or electrical stress, improper installation, misuse, abuse, accident or negligence in use, storage, transportation or handling. This warranty also does not apply to fuses, batteries, or damage from battery leakage. THIS WARRANTY IS IN LIEU OF ALL OTHER WARRANTIES, EXPRESSED OR IMPLIED, INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR USE. NEWPORT CORPORATION SHALL NOT BE LIABLE FOR ANY INDIRECT, SPECIAL, OR CONSEQUENTIAL DAMAGES RESULTING FROM THE PURCHASE OR USE OF ITS PRODUCTS. First printing 2008 © 2008 by Newport Corporation, Irvine, CA. All rights reserved. No part of this manual may be reproduced or copied without the prior written approval of Newport Corporation. This manual has been provided for information only and product specifications are subject to change without notice. Any change will be reflected in future printings. Newport Corporation 1791 Deere Avenue Irvine, CA, 92606 USA Part No. 44951-02, Rev. D Firmware version 2.1.7
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Preface
Confidentiality & Proprietary Rights Reservation of Title: The Newport programs and all materials furnished or produced in connection with them ("Related Materials") contain trade secrets of Newport and are for use only in the manner expressly permitted. Newport claims and reserves all rights and benefits afforded under law in the Programs provided by Newport Corporation. Newport shall retain full ownership of Intellectual Property Rights in and to all development, process, align or assembly technologies developed and other derivative work that may be developed by Newport. Customer shall not challenge, or cause any third party to challenge the rights of Newport. Preservation of Secrecy and Confidentiality and Restrictions to Access: Customer shall protect the Newport Programs and Related Materials as trade secrets of Newport, and shall devote its best efforts to ensure that all its personnel protect the Newport Programs as trade secrets of Newport Corporation. Customer shall not at any time disclose Newport's trade secrets to any other person, firm, organization, or employee that does not need (consistent with Customer's right of use hereunder) to obtain access to the Newport Programs and Related Materials. These restrictions shall not apply to information (1) generally known to the public or obtainable from public sources; (2) readily apparent from the keyboard operations, visual display, or output reports of the Programs; 3) previously in the possession of Customer or subsequently developed or acquired without reliance on the Newport Programs; or (4) approved by Newport for release without restriction. Service Information This section contains information regarding factory service for the source. The user should not attempt any maintenance or service of the system or optional equipment beyond the procedures outlined in this manual. Any problem that cannot be resolved should be referred to Newport Corporation. Copyright and Trademark Information WINDOWSTM is a registered Trademark of Microsoft Corporation LabVIEW is a registered Trademark of National Instruments INC. Visual Basic is a registered Trademark of Microsoft Corporation. Visual C++ is a registered Trademark of Microsoft Corporation.
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Preface
Technical Support Contacts North America & Asia
Europe
Newport Corporation Service Dept. 1791 Deere Ave. Irvine, CA 92606 Telephone: (949) 253-1694 Telephone: (800) 222-6440 x31694
Newport/MICRO-CONTROLE S.A. Zone Industrielle 45340 Beaune la Rolande, FRANCE Telephone: (33) 02 38 40 51 56
Asia Newport Opto-Electronics Technologies 253 Aidu Road, Bld #3, Flr 3, Sec C, Shanghai 200131, China Telephone: +86-21-5046 2300 Fax: +86-21-5046 2323
Newport Corporation Calling Procedure If there are any defects in material or workmanship or a failure to meet specifications, promptly notify Newport's Returns Department by calling 1-800222-6440 or by visiting our website at www.newport.com/returns within the warranty period to obtain a Return Material Authorization Number (RMA#). Return the product to Newport Corporation, freight prepaid, clearly marked with the RMA# and we will either repair or replace it at our discretion. Newport is not responsible for damage occurring in transit and is not obligated to accept products returned without an RMA#. E-mail:
[email protected] When calling Newport Corporation, please provide the customer care representative with the following information:
• • •
Your Contact Information Serial number or original order number Description of problem (i.e., hardware or software)
To help our Technical Support Representatives diagnose your problem, please note the following conditions:
• • • •
Is the system used for manufacturing or research and development?
•
Can you identify anything that was different before this problem occurred?
What was the state of the system right before the problem? Have you seen this problem before? If so, how often? Can the system continue to operate with this problem? Or is the system nonoperational?
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Preface
IMPORTANT NOTE Before plugging the instrument into a PC via a USB communication port, please make sure that the USB Drivers are installed. Run Setup.exe from the Software CD that came with your product. The installation program will configure the PC with the 1918-C USB drivers.
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Preface
Table of Contents EU Declaration of Conformity................................................................ iii Warranty................................................................................................... v Technical Support Contacts ................................................................... vii Table of Contents .................................................................................... ix List of Figures ....................................................................................... xiii List of Tables ........................................................................................ xiv
1
Safety Precautions 1.1
1.2 1.3
2
2.4 2.5 2.6 2.7 2.8 2.9 2.10
3
Definitions and Symbols ............................................................ 15 1.1.1 General Warning or Caution ...........................................15 1.1.2 Electric Shock..................................................................15 1.1.3 TÜV Mark .......................................................................15 1.1.4 European Union CE Mark ...............................................16 1.1.5 Alternating voltage symbol .............................................16 1.1.6 Stand-by...........................................................................16 1.1.7 Frame or Chassis .............................................................16 1.1.8 Waste Electrical and Electronic Equipment (WEEE) .....17 Warnings and Cautions............................................................... 17 1.2.1 General Warnings............................................................18 1.2.2 General Cautions .............................................................18 Location of Labels...................................................................... 19 1.3.1 Rear Panel........................................................................19
General Information 2.1 2.2 2.3
3.3 3.4
21
Introduction ................................................................................ 21 Calibration .................................................................................. 22 Specifications ............................................................................. 22 2.3.1 Physical Specifications:...................................................22 2.3.2 Electrical Specifications ..................................................23 Unpacking and Handling............................................................ 24 Inspection for Damage ............................................................... 24 Available Options and Accessories ............................................ 25 Parts List..................................................................................... 25 Choosing and Preparing a Suitable Work Surface ..................... 26 Electrical Requirements.............................................................. 26 Battery and External Power Supply ........................................... 26
System Overview 3.1 3.2
15
29
Startup Procedure ....................................................................... 29 Front Panel Layout ..................................................................... 29 3.2.1 Front Panel Elements.......................................................29 3.2.2 Understanding the Main Screen ......................................30 Side Panel Layout....................................................................... 30 3.3.1 Side Panel Layout............................................................30 Rear Panel Layout ...................................................................... 32
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Preface
3.4.1 3.4.2
4
System Operation 4.1 4.2
4.3 4.4 4.5 4.6 4.7 4.8 4.9 4.10 4.11 4.12
4.13
5
5.9
35
Side Panel Power Switch and Indicators .................................... 35 4.1.1 Stand-by Switch.............................................................. 35 4.1.2 LED Indicators ............................................................... 35 Front Panel Keys ........................................................................ 36 4.2.1 Setup/Enter Key.............................................................. 36 4.2.2 Esc Key........................................................................... 38 4.2.3 Navigation and Selection Keys....................................... 38 4.2.4 Soft Keys ........................................................................ 38 4.2.5 Dedicated Keys............................................................... 38 Measurement Settings................................................................. 42 4.3.1 Changing the Measurement Settings .............................. 42 4.3.2 Detector Information ...................................................... 44 Power Management .................................................................... 45 Trigger Setup .............................................................................. 46 4.5.1 Trigger Start.................................................................... 46 4.5.2 Trigger Stop.................................................................... 46 Wavelength Setting..................................................................... 47 Display Color.............................................................................. 47 USB Address .............................................................................. 49 Statistics...................................................................................... 49 4.9.1 Graph .............................................................................. 50 Math Functions ........................................................................... 51 Measurement Correction Settings .............................................. 51 Display Modes............................................................................ 52 4.12.1 Numeric Display............................................................. 53 4.12.2 Analog Bar...................................................................... 53 4.12.3 Analog Needle ................................................................ 54 4.12.4 Vertical Chart ................................................................. 55 Optical Meter Firmware Upgrade Procedure ............................. 55
Performing Basic Measurements 5.1 5.2 5.3 5.4 5.5 5.6 5.7 5.8
6
Rear Panel Elements....................................................... 32 Kick Stand Positions....................................................... 32
57
Introduction ................................................................................ 57 Measurement Modes and Units .................................................. 57 CW Measurements (with 918D or 818P Detectors)................... 58 Peak-to-Peak Power Measurements (918D Detectors) .............. 59 Power Ratio and Power Reference measurements ..................... 59 Pulse Energy Measurements (818E Detectors) .......................... 60 Signal Integration Measurements (918D or 818P Detectors)..... 61 Measuring Laser Pulse Energy with an 818P Thermopile Detector (Single Shot)................................................................ 61 RMS Measurements ................................................................... 63
Software Application
65
xi
Preface
6.1 6.2 6.3 6.4
7
Computer Interfacing 7.1 7.2
7.3
8
9.11
105
Introduction .............................................................................. 105 Analog Signal Flow.................................................................. 105 Digitized Signal Flow............................................................... 106 Typical Detector Signals .......................................................... 107 Thermopile Detector Signals.................................................... 108 Pulse Energy Detector Signals ................................................. 108 Peak-to-Peak (Photodiode) Detector Signals ........................... 109 Integration of Detector Signals................................................. 110 Analog Output .......................................................................... 111 Measurement Considerations ................................................... 112 9.10.1 Detector Calibration and Uncertainty............................112 9.10.2 Quantum Detector Temperature Effects........................112 9.10.3 Thermopile Detector Temperature Effects ....................113 9.10.4 Energy Detector Temperature Effects ...........................113 9.10.5 Ambient and Stray Light ...............................................113 9.10.6 Signal Filtering ..............................................................114 Common Measurement Errors ................................................. 115
10 Troubleshooting 10.1 10.2 10.3
69
1918-C Optical Meter Remote Interface Commands................. 69 Command Overview................................................................... 69 Optical Meter Command Description ........................................ 70 8.3.1 Command Glossary .........................................................70 8.3.2 Display Commands .........................................................72 8.3.3 Optical Meter Commands................................................73
Principles of Operation 9.1 9.2 9.3 9.4 9.5 9.6 9.7 9.8 9.9 9.10
67
General Guidelines ..................................................................... 67 Computer Interface Terminology ............................................... 67 7.2.1 Delimiting Punctuation ..........................................67 7.2.2 Carriage Return.....................................................67 7.2.3 Line Feed...............................................................67 7.2.4 (;) Semicolons..................................................................67 7.2.5 Numerical Types............................................68 7.2.6 String Types ......................................................68 USB Communication.................................................................. 68
Communication Command Reference 8.1 8.2 8.3
9
Overview .................................................................................... 65 Connection.................................................................................. 65 General Usage ............................................................................ 66 Menu Structure ........................................................................... 66
117
Power Supply Problems ........................................................... 117 Analog Output Problems .......................................................... 118 Questions and Answers ............................................................ 118
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Preface
11 Maintenance and Service 11.1 11.2 11.3 11.4 11.5
Enclosure Cleaning................................................................... 121 Battery Pack Replacement........................................................ 121 Spare Parts ................................................................................ 122 Obtaining Service ..................................................................... 123 Service Form............................................................................. 124
12 Appendix A – Syntax and Definitions 12.1 12.2
125
Definition of ............................................................... 125 Definition of ............................................................ 126
13 Appendix B – Error Messages 13.1 13.2 13.3 13.4
121
129
Introduction .............................................................................. 129 Command Errors....................................................................... 129 Execution Errors ....................................................................... 130 Device Errors............................................................................ 131
14 Appendix C - Legacy Commands Reference
133
15 Appendix D – Sample Programs
135
15.1 15.2 15.3 15.4 15.5
Programming Samples.............................................................. 135 LabVIEW.................................................................................. 135 Microsoft® Visual Basic .......................................................... 135 Microsoft Visual C++............................................................... 135 Microsoft .NET......................................................................... 135
16 Appendix E – Disassembly Instructions 16.1
137
Disassembly instructions .......................................................... 137
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Preface
List of Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 Figure 12 Figure 13 Figure 14 Figure 15 Figure 16 Figure 17 Figure 18 Figure 19 Figure 20 Figure 21 Figure 22 Figure 23 Figure 24 Figure 25 Figure 26 Figure 27 Figure 28 Figure 29 Figure 30 Figure 31 Figure 32 Figure 33 Figure 34 Figure 35 Figure 36 Figure 37 Figure 38 Figure 39 Figure 40 Figure 41 Figure 42 Figure 43
General Warning or Caution Symbol............................................. 15 Electrical Shock Symbol ................................................................ 15 TÜV Mark...................................................................................... 15 CE Mark ......................................................................................... 16 Alternating Voltage Symbol .......................................................... 16 Stand-by Symbol............................................................................ 16 Frame or Chassis Terminal Symbol............................................... 16 WEEE Directive Symbol ............................................................... 17 Locations of labels on the rear panel.............................................. 19 1918-C Optical Meter hard case .................................................... 25 Rear panel with the battery cover removed.................................... 27 Front Panel Layout......................................................................... 29 Side Panel Layout .......................................................................... 31 Rear panel ...................................................................................... 32 Kickstand in the first angled position............................................. 33 Power Switch ................................................................................. 35 Front Panel keys............................................................................. 36 Navigation/Selection and Setup/Enter keys................................... 37 Main screen .................................................................................... 37 Measurement Settings screen......................................................... 37 Soft keys......................................................................................... 38 Dedicated keys ............................................................................... 38 Manual Range mode ...................................................................... 39 Auto Range mode........................................................................... 39 This screen is displayed after pressing the Config soft key ........... 39 Mode selection screen .................................................................... 40 Measurement is on hold ................................................................. 40 Filter selection screen..................................................................... 40 Filter configuration screen ............................................................. 41 Digital Filter editing....................................................................... 41 Wavelengths screen........................................................................ 41 Zero Selection ................................................................................ 42 Measurement Settings screen......................................................... 42 Accessing the Power Mangement screen...................................... 45 Power Mangement Settings screen ............................................... 45 Accessing the Trigger Setup screen ............................................... 46 Predefined color schemes............................................................... 48 Setup screen ................................................................................... 48 System Settings screen................................................................... 48 About screen .................................................................................. 49 Statistics screen .............................................................................. 49 Graph screen .................................................................................. 50 Math field....................................................................................... 51
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Preface
Figure 44 Figure 45 Figure 46 Figure 47 Figure 48 Figure 49 Figure 50 Figure 51 Figure 52 Figure 53 Figure 54 Figure 55 Figure 56 Figure 57 Figure 58 Figure 59 Figure 60 Figure 61 Figure 62 Figure 63 Figure 64 Figure 65
Math configuration screen.............................................................. 51 Measurement Settings .................................................................... 52 Correction Settings......................................................................... 52 Mode selection screen .................................................................... 52 The Numeric display ...................................................................... 53 Analog Bar ..................................................................................... 53 Auto Zoom ..................................................................................... 54 Analog Needle display ................................................................... 54 Vertical chart with 10 measurements per line................................ 55 Vertical chart with 1 measurement per line ................................... 55 Measuring Laser Pulse Energy via a Thermopile in CW Integrate Mode .............................................................................................. 62 Application front panel................................................................... 65 Application Advanced Options (Configuration Tab)..................... 66 1918-C Optical Meter Analog Signal Flow Diagram .................. 105 Thermopile Signals exhibit 1 to 10 second time constants. ......... 108 Typical Newport Energy Detector Signal Waveform .................. 109 Negative Baseline Voltage. .......................................................... 109 Time Varying Signal Measurements............................................ 110 Integrated Energy Via a Trapezoid Approximation..................... 110 Measuring Laser Pulse Energy with a Thermopile. ..................... 111 Battery Replacement .................................................................... 121 Disassembled 1918-C Optical Meter ........................................... 138
List of Tables Table 1 Table 2 Table 3 Table 4 Table 5 Table 6 Table 7 Table 8
Available Measurement Modes and Valid Units. .......................... 58 Root level Commands/Queries Summary ...................................... 70 Tree Level Commands/Queries Summary ..................................... 72 Analog Signal Flow Paths. ........................................................... 106 Analog Output Range Table......................................................... 111 Common Measurement Errors ..................................................... 115 Spare Parts.................................................................................... 122 Legacy Commands Reference...................................................... 134
1
Safety Precautions
1.1
Definitions and Symbols The following terms and symbols are used in this documentation and also appear on the 1918-C Optical Meter where safety-related issues occur.
1.1.1
General Warning or Caution
Figure 1
General Warning or Caution Symbol
The Exclamation Symbol in the figure above appears in Warning and Caution tables throughout this document. This symbol designates an area where personal injury or damage to the equipment is possible.
1.1.2
Electric Shock
Figure 2
Electrical Shock Symbol
The Electrical Shock Symbol in the figure above appears throughout this manual. This symbol indicates a hazard arising from dangerous voltage. Any mishandling could result in irreparable damage to the equipment, and personal injury or death.
1.1.3
TÜV Mark
Figure 3
TÜV Mark
The presence of the TÜV mark indicates that it has been designed, tested and certified as complying with the safety requirements in conjunction with the issuance of this mark.
16
Safety Precautions
1.1.4
European Union CE Mark
Figure 4
CE Mark
The presence of the CE Mark on Newport Corporation equipment means that it has been designed, tested and certified as complying with all applicable European Union (CE) regulations and recommendations.
1.1.5
~
Alternating voltage symbol
Figure 5
Alternating Voltage Symbol
This international symbol implies an alternating voltage or current.
1.1.6
Stand-by
Figure 6
Stand-by Symbol
The Stand-by Symbol in the figure above represents a power switch position. This symbol represents a Stand-by condition in which some circuitry is still on. In the case of the 1918-C Optical Power Meter, in the Stand-by position the charging circuit is still on, while the main processing circuit is off.
1.1.7
Frame or Chassis
Figure 7
Frame or Chassis Terminal Symbol
The symbol in the figure above appears on the 1918-C Optical Meter. This symbol identifies the frame or chassis terminal
Safety Precautions
1.1.8
17
Waste Electrical and Electronic Equipment (WEEE)
Figure 8
WEEE Directive Symbol
This symbol on the product or on its packaging indicates that this product must not be disposed of with regular waste. Instead, it is the user responsibility to dispose of waste equipment according to the local laws. The separate collection and recycling of the waste equipment at the time of disposal will help to conserve natural resources and ensure that it is recycled in a manner that protects human health and the environment. For information about where the user can drop off the waste equipment for recycling, please contact your local Newport Corporation representative. See Section 16 for instructions on how to disassemble the equipment for recycling purposes.
1.2
Warnings and Cautions The following are definitions of the Warnings, Cautions and Notes that are used throughout this manual to call your attention to important information regarding your safety, the safety and preservation of your equipment or an important tip.
WARNING Situation has the potential to cause bodily harm or death.
CAUTION Situation has the potential to cause damage to property or equipment.
NOTE Additional information the user or operator should consider.
18
Safety Precautions
1.2.1
General Warnings Observe these general warnings when operating or servicing this equipment:
• Heed all warnings on the unit and in the operating instructions. • Do not use this equipment in or near water. • This equipment is grounded through the grounding conductor of the • • • •
• •
power cord. Route power cords and other cables so they are not likely to be damaged. Disconnect power before cleaning the equipment. Do not use liquid or aerosol cleaners; use only a damp lint-free cloth. Lockout all electrical power sources before servicing the equipment. To avoid fire hazard, use only the specified fuse(s) with the correct type number, voltage and current ratings as referenced in the appropriate locations in the service instructions or on the equipment. Only qualified service personnel should replace fuses. To avoid explosion, do not operate this equipment in an explosive atmosphere. Qualified service personnel should perform safety checks after any service.
1.2.2
General Cautions
Observe these cautions when operating or servicing this equipment:
• If this equipment is used in a manner not specified in this manual, the • • • • • • • • •
protection provided by this equipment may be impaired. Do not position this product in such a manner that would make it difficult to disconnect the power cord. Use only the specified replacement parts. Follow precautions for static sensitive devices when handling this equipment. This product should only be powered as described in the manual. There are no user-serviceable parts inside the 1918-C Optical Meter with the exception of the battery. Use only the Newport Model 1918-BAT battery. Use only the Newport Model 1918-PS external power supply. To prevent damage to the equipment, read the instructions in the equipment manual for proper input voltage. Adhere to good laser safety practices when using this equipment.
Safety Precautions
19
1.3
Location of Labels
1.3.1
Rear Panel Markings on the rear panel identify the instrument compliance with different standards and regulations. The labels are located in the middle of the rear panel.
Location of Labels
Figure 9
Locations of labels on the rear panel
20
Safety Precautions
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2
General Information
2.1
Introduction The 1918-C Optical Meter is designed to provide a powerful combination of features to measure optical power and energy of near-monochromatic or monochromatic sources. The instrument is powered by internal, rechargeable batteries, or via the AC wall-plug, hence making it a useful tool for both stationary and portable applications. Use of the extensive measurement modes and features have been simplified with an intuitive menu driven structure that provides quick access to all modes, features and settings. Some of the prominent specifications and features that will simplify your calibrated measurement applications are in the following:
•
• • • • • •
Compatibility with Photodiode, Thermopile and Pyroelectric detectors. (Low-Power (Semiconductor) Family, High-Power (Thermopile) Family, Energy (Pyroelectric) Family, PMT, GaN, PbS, PbSe, and HgCdZnTe) Measurement rate up to 4 kHz with internal signal sampling rate of 250 kHz. Multiple measurement modes for power and energy measurements: Single, Continuous, Integrated, and Peak-to-Peak . Software suite, including LabVIEW drivers and Windows application. 250,000 internal data point storage. External USB flash-memory compatibility. USB Device interface.
The full color TFT 4” LCD renders excellent visibility both with the naked eye and laser goggles for single screen rendering of plotted and enumerate results. Measurements can be displayed in W, Joules, Amps, Volts, Hertz, dBm, dB, Sun or relative units, either directly or as relative ratio measurements from present or stored values. Statistical capabilities include the computation of Min, Max, Max-Min, Mean and Standard Deviation. Additional features such as digital and analog filtering, and data storage of up to 250,000 readings per channel are also offered. Newport’s experience with calibration, together with N.I.S.T. calibration traceability and high precision Optical Meters provide users with accurate measurements and exceptional inter-instrument correlation. In R&D, QA/QC,
22
General Information
and manufacturing environments, the 1918-C Series optical meters enable users to benefit from high correlation between multiple locations at a priceto-performance ratio second to none. Among all the other practical tools provided, remote controlling with a computer and synchronization to other instruments are simplified with the inclusion of LabVIEW drivers, tools to develop in the .NET environment and a high-speed software utility that fully utilized the optical meter’s ability to sample at 250 kHz and transfer data via a Full-Speed USB interface (11 Mbps).
2.2
Calibration Calibration of the optical meter is done at the factory by defining a slope and offset, for all ranges as determined for each detector type. Newport recommends annual factory re-calibration to ensure the continued accuracy of optical meter measurements. Please refer to the “Maintenance and Troubleshooting” section for contact information for re-calibration of your optical meter.
1
2.3
Specifications
2.3.1
Physical Specifications: Dimensions:
5.4 x 7.6 x 2.4 inch (137 x 193 x 61 mm)
Weight:
max. 2.3 lb
Enclosure:
Plastic molded case with a kick stand.
Connectors:
Optical Detector 15-Pin D-Sub, Analog Output 3.5 mm Jack, USB-A Host, mini-B USB Device, DC Input 2.1 mm Power Jack.
Power:
90-264 VAC, 50/60 Hz, 33 Watts with 1918-EXT-PS External Power Supply
Display:
Graphical LCD ¼ VGA, 4 inch diagonal
Display Update Rate:
up to 20 Hz for selected graphical modes
Operating Environment1:
5°C to 40°C; < 70% RH non-condensing
Storage Environment:
-20°C to 60°C; < 90% RH non-condensing
Altitude
< 3000m
Installation Category
II
Pollution Degree
2
Use Location
Indoor use only.
Charging battery up to 35°C
General Information
2.3.2
23
Electrical Specifications
DC Current Measurement (Low-Power, Semiconductor Photodiode) Signal Range
1,2
0
1
2
3
4
2.50 µA
25.0 µA
250 µA
2.50 mA
25 mA
10 pA
100 pA
1.00 nA
10.0 nA
100 nA
480 Hz
4 kHz
43 kHz
170 kHz
500 kHz
Accuracy (Filtered)
0.2%
0.2%
0.2%
0.2%
0.2%
Accuracy (Maximum Measurement Rate=4 kHz)
1.0%
1.0%
1.0%
1.0%
1.0%
100 dB
100 dB
100 dB
100 dB
100 dB
Full-Scale Current Resolution (Filtered) 6
Bandwidth (Unfiltered)
Signal to Noise Ratio
1
Peak-Peak Current Measurement (Low-Power, Semiconductor Photodiode) 2,3
0
1
Full-Scale Current
2.50 µA
Resolution
76.3 pA
Signal Range
Accuracy Bandwidth
6
Maximum Pulse Repetition Rate
4
2
3
4
25.0 µA
250 µA
2.50 mA
25 mA
763 pA
7.63 nA
76.3 nA
763 nA
1.0%
1.0%
1.0%
1.0%
1.0%
480 Hz
4 kHz
43 kHz
170 kHz
500 kHz
480 Hz
4 kHz
4 kHz
4 kHz
4 kHz
D.C. Voltage Measurement (Thermopile) 2,3
0
1
2
3
4
5
Full-Scale Voltage
2.5mV
25.0 mV
250 mV
2.50 V
25.0 V
130 V
Resolution
76.3 nV
763 nV
7.63 µV
76.3 µV
763 µV
3.96 mV
Accuracy 1 (Filtered)
0.2%
0.2%
0.2%
0.2%
0.2%
0.2%
Accuracy (Maximum Measurement Rate=2 kHz)
1.0%
1.0%
1.0%
1.0%
1.0%
1.0%
600 kHz
1000 kHz
1000 kHz
1000 kHz
400 kHz
1000 kHz
100dB
100dB
100dB
100dB
100dB
100dB
3
4
5
Signal Range
Bandwidth
6
Signal to Noise Ratio
1
Pulse Voltage Measurement (Energy, Pyroelectric) 2,3
0
1
Full-Scale Current
2.5mV
25.0 mV
250 mV
2.50 V
25.0 V
130 V
Resolution
76.3 nV
763 nV
7.63 µV
76.3 µV
763 µV
3.96 mV
1.0%
1.0%
1.0%
1.0%
1.0%
1.0%
600 kHz
1000 kHz
1000 kHz
1000 kHz
400 kHz
1000 kHz
2 kHz
2 kHz
2 kHz
2 kHz
2 kHz
2 kHz
Signal Range
Accuracy Bandwidth
6
Maximum Pulse Repetition 5 Rate
2
24
General Information
RMS Measurement Maximum Pulse Repetition Rate
2 kHz
4 kHz
Accuracy
1.0%
2.0 %
Analog Output Output Range
0
1
2
1V
2V
5V
Accuracy
1.0 %
1.0 %
1.0 %
Linearity
0.3%
0.3%
0.3%
Full Scale Voltage (Load > 100 kΩ)
Trigger Level Programmable Level Resolution
0…100 % Full Scale 0.39 % Full Scale
1
With 5Hz filter on. Listed signal ranges specify meter capability. Available signal ranges are detector dependent. 3 Maximum measurable signal is detector dependent. 4 While the maximum repetition range may equal the bandwidth, it really depends on the signal duty-cycle or the signal shape. 5 The Maximum Repetition Rate refers to the meter pulse-by-pulse measuring capability. Due to its high bandwidth, the 1918-C can take in signals with higher repetitive rates and outputs them undistorted at the Analog Output. 6 The instrument bandwidth is determined by the detector used. Please refer to Newport Corporation’s complete offering on detector type. The specified bandwidth is measured from the instrument input (detector) to the Analog Output BNC. 2
2.4
Unpacking and Handling It is recommended that the 1918-C Optical Meter be unpacked in a lab environment or work site. Unpack the system carefully; small parts and cables are included with the instrument. Inspect the box carefully for loose parts before disposing of the packaging. You are urged to save the packaging material in case you need to ship your equipment in the future.
2.5
Inspection for Damage The 1918-C Optical Meter is carefully packaged at the factory to minimize the possibility of damage during shipping. Inspect the box for external signs of damage or mishandling. Inspect the contents for damage. If there is visible damage to the instrument or accessories upon receipt, inform the shipping company and Newport Corporation immediately.
General Information
25
WARNING Do not attempt to operate this equipment if there is evidence of shipping damage or you suspect the unit is damaged. Damaged equipment may present additional hazards to you. Contact Newport technical support for advice before attempting to plug in and operate damaged equipment.
2.6
Available Options and Accessories Newport Corporation also supplies temperature controlled mounts, lenses, and other accessories. Please consult with your representative for additional information.
2.7
Parts List
Battery
External Power Supply And detachable power cord
1918-C Optical Meter
Figure 10
1918-C Optical Meter hard case
The following is a list of parts included in the hardcase (Figure 10) with the 1918-C Optical Meter: 1. A CD-ROM containing the User’s Manual, Software Drivers and Utilities. (A PDF version of the manual can also be downloaded from the Newport website at www.Newport.com). 2. Battery Pack (1918-BAT).
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General Information
3. External Power Supply (1918-PS) and detachable power cord (1918-PSC). If you are missing any of these items or have questions about the items you have received, please contact Newport Corporation.
2.8
Choosing and Preparing a Suitable Work Surface The 1918-C Optical Meter may be placed on any reasonably firm table or bench during operation. The kickstand can be rotated to two angles to improve visibility of the LCD display, as needed. Provide adequate distance between the 1918-C Optical Meter and adjacent walls for ventilation purposes. Approximately 2-inch spacing for all surfaces is adequate.
2.9
Electrical Requirements Before attempting to power up the unit for the first time, the following precautions must be followed:
• If the power supply is equipped with a 3-prong plug, connect the instrument to properly earth-grounded 3-prong receptacle only.
WARNING If the power supply is equipped with a 3-prong plug, connect the instrument to properly earth-grounded, 3-prong receptacles only. Failure to observe this precaution can result in severe injury.
• Have a qualified electrician verify the wall socket that will be used is properly polarized and properly grounded.
2.10
Battery and External Power Supply CAUTION The battery needs to be charged for at least 8 hours before using the optical meter without the external power supply.
The 1918-C Optical Meter is shipped from the factory with the battery removed from the unit. Install the battery before plugging the external power supply and before turning on the unit. To install the battery first remove the battery compartment cover from the back of the unit. Connect the 5-pin battery connector to the corresponding connector inside the battery compartment (Figure 11). The connector is keyed and can only be inserted in one direction so please be careful to properly align the connector pins. Carefully fold the battery wires inside the battery
General Information
27
compartment so that the wires will not put pressure on the battery compartment cover. Close the cover and make sure it latches in place.
Battery Connector
Battery
Figure 11
Rear panel with the battery cover removed
When the optical meter is turned on for the first time the battery needs to be charged for at least 4 hours. The optical meter can be used while the battery is being charged. It is recommended that the external power supply not be removed during the first 4 hours of charging.
CAUTION The battery needs to be removed if the instrument is going to be unused for more than 3 weeks. Failure to do so may result in over-discharging the battery which drastically reduces the battery life or may cause battery breakdown.
AC power is supplied through an external power supply that provides in-line transient protection and RF filtering. This power supply is universal which means it can work at 90-264 VAC and 50/60 Hz.
CAUTION Permanent damage may occur to the optical meter if external powers supply other than the Newport 1918-PS is used. Please call Newport Corporation if extra power supplies are needed for a particular setup.
CAUTION Do not operate with a line voltage that is not within 90-264 VAC.
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General Information
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3
System Overview
3.1
Startup Procedure Provided that the Optical Meter has been installed in an appropriate environment and its external power supply power cord is connected to a working electrical outlet, power-up the Optical Meter by pressing the power button on the upper right corner of the left side panel. The battery will start charging. If the Optical Meter is turned on for the first time, make sure the external power supply is not unplugged from the AC outlet for at least 4 hours. During charging, the Optical Meter can be used for measurements. At the end of the charging time, the Optical Meter can be used without the external power supply. For the highest precision and accuracy, the 1918-C Optical Meter should be allowed to warm up for one hour before being used for measurements.
3.2
Front Panel Layout
Figure 12
3.2.1
Front Panel Layout
Front Panel Elements The front panel of the 1918-C features the following elements:
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System Overview
• • • •
A faceplate with a 4” active color liquid crystal display Setup/Enter and Esc keys Rubberized horizontal (left/right) and vertical (up/down) arrow keys Four rubberized blank keys below the display (referred to as “soft keys” later in the manual, as their function depends on the text on the screen above the key.) • Six rubberized buttons with dedicated functions – Range, Mode, Hold, Filter, Lambda (λ), Zero.
3.2.2
Understanding the Main Screen The main screen is displayed after startup (Figure 12). The middle portion of the main screen is a real-time display of power measured in last used units, and the lower half of the main screen is a row of four labels for actions that the keys below them will activate. When an annunciator label is visible, its function is enabled. If the annunciator appears on the display as an unlabeled key, the function it represents is currently disabled. Annunciators loosely correspond to keypad keys, which are used either alone or in combination with the navigation and selection keys to control annunciator functions.
3.3
Side Panel Layout Input Connectors
The input connectors are on the side panel. The 1918-C Optical Meter supports input from external detectors through a DB15 detector connector. The external power supply is plugged in the DC INPUT connector. Output Connectors
The 1918-C Optical Meter has an analog output, which enables direct monitoring of a detector through an oscilloscope or voltmeter.
3.3.1
Side Panel Layout The side panel is a brushed aluminum plate with input and output connectors, a power switch, and LED indicators (Figure 13)
• • • • •
Stand-by switch. This is a push-on/push-off button for turning the unit on or off. Ground Pin. The user can connect the Optical Meter to an Earth Ground for sensitive measurements. 15-Pin D-Sub Optical Detector Input. 3.5 mm Jack Analog Output. Mini USB Connector labeled USB PC. This connector is used for sending remote commands to the Optical Meter from a PC. The connection to a computer is done via a USB cable Type "A" Male Connector to Type "Mini-B" Male Connector.
System Overview
•
31
USB “A” connector labeled USB MEM. This connector is used for saving the data on a USB Memory and for firmware upgrades.
Analog Out
Stand-by Switch
Mini USB Connector USB “A” Connector Charge Status Indicator 15-pin D-Sub Detector Connector
Power Indicator
DC Input Connector
Grounding Pin
Figure 13
Side Panel Layout
WARNING To avoid electrical shock hazard, connect the instrument to properly earth-grounded, 3-prong receptacles only. Failure to observe this precaution can result in severe injury.
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System Overview
3.4
Rear Panel Layout
Battery compartment cover
Labels
Kickstand
Figure 14
3.4.1
Rear panel
Rear Panel Elements The rear panel of the 1918-C features the following elements (Figure 14):
• Battery compartment cover • Kickstand • Labels Markings on the rear panel identify the instrument compliance with different standards and regulations.
CAUTION There are no user-serviceable parts inside the Optical Meter. Work performed inside the Optical Meter by persons not authorized by Newport may void the warranty.
3.4.2
Kick Stand Positions The instrument can be used in 4 viewing angles, allowing the user to adjust for the height of the work surface and lighting conditions:
• Laying on its back side in the horizontal position • Standing up on its bottom side in the vertical position • At two angled positions, by moving the kick-stand into two, preconfigured notches, manufactured into the instrument body.
System Overview
33
Figure 15
Kickstand in the first angled position
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System Overview
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4
System Operation
4.1
Side Panel Power Switch and Indicators
4.1.1
Stand-by Switch
Figure 16
Power Switch
The Stand-by switch is located on the side panel and is a toggle button. It turns the unit on or in stand-by. When in stand-by, the unit is not fully turned off. In stand-by, the 1918-C Optical Meter will charge the battery, while all the other functions are off.
4.1.2
LED Indicators The instrument has two LED indicators – one for Power and one for Status. Both of these are located on the Side Panel.
4.1.2.1
Power Indicator The Power Indicator shows the current state of the battery charging circuit when the external power supply is powered and connected to the instrument. This indicator operates even when the unit is turned OFF. This indicator is not lit when the external power supply is disconnected from the instrument or is not connected to an external AC power source.
NOTE The power indicator is not lit when the unit is operating from its internal battery.
When external power is applied, there are four states for this indicator – Unlit, Flashing Red, Continuous Red, and Continuous Green. The Power Indicator will be Continuously Green when the battery charge circuitry detects a fully charged battery. The Power Indicator will be Continuously Red while the battery is being charged.
36
System Operation
The Power Indicator will be Flashing Red after external power is applied and until the battery charge circuitry determines that the instrument’s internal battery is safe to charge. This may range from less than a second to several minutes, depending on the initial state of the battery. Even when external power is applied to the instrument, the Power Indicator will not be lit when the charging circuitry detects a failed, defective, or missing battery. It is acceptable to operate the unit without a battery using just the external supply. 4.1.2.2
Status Indicator The Status Indicator will switch every few seconds between Green and Unlit when the instrument is turned ON and is operating normally.
4.2
Front Panel Keys The front panel keys are organized in three groups (see Figure 17).
• Navigation Keys • Reconfigurable Keys (also called Soft Keys) • Escape (ESC) Key
Navigation Keys
Escape Key
Dedicated Keys
Reconfigurable (Soft) Keys
Figure 17
4.2.1
Front Panel keys
Setup/Enter Key The Setup/Enter key is placed to the right of the display (Figure 18). This key has dual functionality. From the main screen (Figure 19) press this key to display the Measurement Settings screen (Figure 20). Also, use this key while
System Operation
37
any secondary menu is displayed to complete entering data, or to exit the current secondary screen.
Figure 18
Navigation/Selection and Setup/Enter keys
Figure 19
Figure 20
Main screen
Measurement Settings screen
Refer to Section 4.3 for more information about the measurement settings.
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System Operation
4.2.2
Esc Key The Esc key (Figure 17 and Figure 18) is used to cancel the current action. When in a secondary screen or menu, it will close the current screen or menu and the instrument will return to the main screen (Figure 19).
4.2.3
Navigation and Selection Keys Navigation through and selection of data in the display is done with the top right group of four arrows keys and with the Setup/Enter key (Figure 18). If the instrument is in Setup mode or in any configuration screens, pressing the arrow keys will select different setup modes as displayed by the current screen.
4.2.4
Soft Keys Below the screen are a group of four keys (Figure 21). Their function varies, depending on the measurement mode or the setup screen. They are designed to provide context sensitive functionality to the user. The label displayed above each key indicates their function.
Figure 21
4.2.5
Soft keys
Dedicated Keys Six dedicated function keys are at the bottom right portion of the front panel (Figure 22). Each of these keys can be used for quick access to the given function.
Figure 22
Dedicated keys
System Operation
39
Range
Pressing this key reconfigures the Soft keys at the bottom of the screen as in Figure 23. From this screen the user has two options. • One is to toggle Auto/Manual Range mode. This is accomplished by pressing the left-most Soft key. If the meter current configuration is Manual mode the left-most Soft key is labeled Auto to allow the user to change the Range selection in Auto Range Mode. This can be seen in Figure 23, where the range is 1.000 W indicating a manual mode. If the instrument is in Auto Range Mode, the left most key is labeled Manual. The user may return to the main screen by pressing the ESC key (see Figure 24). • The other option is to press the right-most Soft key, which is labeled Config. This action displays the Range Configuration screen. Here the user can select a certain range or even Auto Range with the Navigation/Enter keys. The number of ranges depends on the detector used (see Section 2.3.2). Once a range is selected the instrument returns to the main screen. While in Range Configuration screen, the user may cancel the selection by hitting the ESC key.
Figure 23
Figure 24
Manual Range mode
Auto Range mode
Figure 25 This screen is displayed after pressing the Config soft key
40
System Operation
Mode
The Mode key displays a screen as in Figure 26. Using Navigation/Enter keys, the user can select different measurement modes or display modes according to his/her application. The ESC key cancels the selection and brings the instrument back to the main screen. Figure 26
Mode selection screen
Hold
The Hold key toggles between holding the current measurement or running freely. When in Hold mode the numeric display freezes and the upper left corner of the display reads Hold (see Figure 27). The display starts running when the Hold key is pressed again. The ESC key has no effect on Hold status. Figure 27
Measurement is on hold
Filter
The Filter key allows the user to apply Analog or Digital Filters or both to the detector signal. This key brings a screen as in Figure 28. The Soft keys are reconfigured for the filter selection. Counting from left to right, the first key applies only the Analog filter to the detector signal, the second applies only the Digital Filter, and the third applies both filters. When the filters are selected, the corresponding label above the soft key has a highlighted background and the filter name is displayed in the upper left corner.
Figure 28 Filter selection screen
System Operation
The fourth Soft key is used for filter configuration. When selected, a screen as in Figure 29 is displayed. Using the Navigation/Enter keys the user can select the filter of choice. If the Enter key is not pressed, the ESC key cancels the selection and brings the instrument back to the main screen. If the Enter key is pressed, a selection is made, and the instrument goes back to the main screen. The digital filter values can be edited (Figure 30). When one of the digital filter values is selected, the right most soft key becomes Edit Value. Pressing this Soft key displays a cursor on top of the first digit of the edited filter value. The Navigation Up/Down keys modify the digit, while the Left/Right keys move the cursor to the next digit. When finished, press the Enter key to store the new digital filter value and press Enter again to select the new value and exit the Filter configuration screen.
41
Figure 29
Filter configuration screen
Figure 30
Digital Filter editing
Lambda (λ) Key
The Lambda (λ) key brings the Default and Custom Wavelengths screen (Figure 31). This screen allows the user to choose a default wavelength for the measurement in progress, or to choose a custom wavelength. See Section 4.6 for more details. Figure 31 Wavelengths screen
42
System Operation
Set Zero Offset (Zero Key)
The Zero Offset key, or short, Zero key is used to temporarily zero the instrument for the measurement in progress. When the user presses this key, the instrument takes the displayed numeric value as offset and subtracts it from all the subsequent measurements. When the instrument is zeroed the offset value is displayed on the main screen above the numeric value (see Figure 32).
Figure 32 Zero Selection
The Zero key toggles the offset on or off. The ESC key has no effect on the Zero function.
4.3
Measurement Settings The Measurement Settings screen has dual functionality: • One is the convenience the user has to change all the measurement settings within one screen. • The other is information presented to the user about the detector used. From the default screen, when pressing the Setup/Enter key, the 1918-C displays the Measurement Settings screen as in Figure 33.
4.3.1
Figure 33
Measurement Settings screen
Changing the Measurement Settings Within the Measurement Settings screen the user can select the Wavelength, Range, Range Type, Beam Attenuator, Analog Filter selection, Digital Filter selection, Measurement Units, Measurement Mode, Spot Size and the Number of Digits displayed.
4.3.1.1
Wavelength Selection
With the Navigation/Selection keys bring the cursor on top of the Wavelength field. Hit the Enter key. A drop-down menu appears with the custom wavelength values (see Section 4.6 for more information about the wavelength custom values). Select the desired wavelength and hit Enter. 4.3.1.2
Range Selection and Range Type (Rng. type)
The Range field has dual functionality:
System Operation
43
• One is to display the current selected range whether it was selected by the user, in Manual Range Mode, or by the system, in Auto Range Mode. • The other is to allow the user to change the range. With the Navigation/Selection keys bring the cursor on top of the Range field. Hit the Enter key. A drop-down menu appears with the available ranges in the selected units. Select the desired range and hit Enter. If the unit was in Auto Range mode, once a range is selected here, it will switch the system to Manual Range Mode. To bring it back to Auto Range Mode, navigate to Range Type (Rng. type) and change the range to Auto Range Mode. Also, the user has another option to bring the Optical Meter back into the Auto Range Mode. This can be done from the default screen where the user can change the Range to Auto Range Mode with the Range Dedicated key (see Section 4.2.5).
NOTE The Auto Range Mode is disabled for Pulse Energy Measurements 818E Detectors. See Section 5.6 for more details.
4.3.1.3
Attenuator On/Off
If the detector is equipped with an integrated attenuator (e.g. 918D Series), the 1918-C detects its status (ON or OFF) and displays it in the Attenuator field. The user has the option to manually set the attenuator to ON or OFF for detectors that have attenuators that can be manually mounted on the detector (e.g. 818 Series). To change the attenuator status, bring the cursor on top of the Attenuator field. Hit the Enter key. A drop-down menu appears with the ON/OFF option. Select the setting and hit Enter. 4.3.1.4
Analog and Digital Filter Selection
With the Navigation/Selection keys bring the cursor on top of the Analog or Digital field. Hit the Enter key. A drop-down menu appears with the available filter settings. Select the desired filter and hit Enter. The Analog and Digital filter configuration can be accessed any time with the Filter dedicated key. Refer to Section 4.2.5 for details. 4.3.1.5
Units Selection
With the Navigation/Selection keys bring the cursor on top of the Units field. Hit the Enter key. A drop-down menu appears with the available units. Select the desired units and hit Enter. 4.3.1.6
Mode Selection
This setting allows the user to change the measurement mode. The available modes are as follows:
44
System Operation
• • • • • • • •
Continuous Wave Continuous Run (CW Cont.) Continuous Wave Single Shot (CW Single) Continuous Wave Integral (CW Integ.) Peak-to-Peak Continuous Run (Pk-Pk Cont.) Peak-to-Peak Single Shot (Pk-Pk Single) Pulse Mode Continuous Run (Pulse Cont.) Pulse Mode Single Shot (Pulse Single) RMS Measurements (RMS) Refer to Section 5, Performing Basic Measurements, for detailed information regarding these modes.
4.3.1.7
Spot Size
This setting allows users to change the spot size. The default spot size is set to be same as the detector size. The spot size can be modified by navigating the cursor to this setting, and pressing the Setup/Enter key. The value then becomes editable; each digit in the value can be changed by pressing Up/Down arrow keys, and different digits can be selected by pressing Left/Right arrow keys. The desired value can be accepted by pressing Setup/Enter key. 4.3.1.8
Number of Digits Setting
The 1918-C displays a default 4 number of digits. To change these settings bring the cursor on top of the Num. Digits field. Hit the Enter key. A dropdown menu appears with the option of 3, 4 or 5 digits. Select the desired number of digits and hit Enter. 4.3.1.9
Offset Field
On the right column of the Measurement Settings the unit displays the Offset stored when the user hits the Zero dedicated key. This value can be cleared or updated if the unit is in the default screen and Zero is pressed (see Section 4.2.5 for more information).
4.3.2
Detector Information The Measurement Settings screen displays information about the detector used based on the data available in the detector calibration module or detector internal memory. The available data are the detector model number (Detector), the detector serial number (S/N), the detector temperature (Det. temp.) if the detector has an internal temperature sensor, and the detector responsivity (Responsivity).
System Operation
4.4
45
Power Management The Power Management Settings screen is used to select the instrument’s power savings behavior. Reducing the intensity of the LCD Display backlight significantly reduces the instrument’s power consumption and thereby increases the time the instrument can be operated while powered from its internal battery. Power consumption is further reduced when the instrument is in its “Standby” mode.
Figure 34 Accessing the Power Mangement screen
The Power Management Settings screen can be accessed from the Measurement Settings screen (Figure 34) by pressing the Power soft key. The Power Management screen is shown in Figure 35. The left column settings are applicable while the instrument is operating on battery power. The right column settings are applicable when the instrument is powered via the external power supply.
Figure 35
Power Mangement Settings screen
By default, the LCD Display Backlight is set for full (maximum) intensity. After a selected period of time without input from the keypad or communications via the USB interfaces, the instrument will enter its “Reduced Backlight” mode. In this mode the instrument functions normally; i.e., it is still capable of taking measurements; but the backlight is dimmer. The display will return to its normally bright intensity when any key on its keypad is actuated or when a command is received via the USB interface. The Backlight Level can be changed from OFF to 100% in increments of 25%. The Backlight Pwr. settings are used to select the time from the last keypad actuation, or USB command, until the instrument enters “Reduced Backlight” mode. The available settings are 1 minute, 5 minutes, 30 minutes, 2 hours, and Always. When “Always” is selected, the display is always at the maximum backlight intensity. In Standby mode, measurements are disabled and the LCD Display Backlight is completely turned OFF, but the instrument will continue to monitor for keypad actuations and USB commands. When either of these “wake-up” events occurs, the instrument will read the detector; if the detector was not
46
System Operation
changed while the instrument was in Standby mode, it will then revert to the user settings in effect when it entered Standby mode. The Standby settings on the Power Management Settings screen are used to select the time from the last keypad actuation, or USB command, until the instrument enters Standby mode. The available settings are 1 minute, 5 minutes, 30 minutes, 2 hours, and never. When Never is selected, the instrument never enters Standby mode.
4.5
Trigger Setup The Trigger Setup screen can be accessed from the Measurement Settings (Figure 36). Pressing the Trigger soft key gives the user a few choices to setup the trigger according to the measurement needs. The 1918-C Series has an advanced Trigger set that allows the user to synchronize the measurements. Synchronization can be achieved with Trigger Start and Trigger Stop which can be set both from the trigger setup screen or with external commands.
4.5.1
Figure 36
Accessing the Trigger Setup screen
Trigger Start The Trigger Start is an event that tells the system when to take a measurement or a group of measurements. It can be set in different ways. • Continuous. The system is always triggered • Soft Key. The system can be triggered with a Soft Key that appears in the main screen. • Command. The system is triggered with an external command, PM:TRIG:STATE (Section 8.3.3). The Trigger Start can also be set with an external command PM:TRIG:START (Section 8.3.3).
4.5.2
Trigger Stop The Trigger Stop is an event that tells the system when to stop taking measurements. In the case of a single measurement, a trigger stop event arms the system for the next measurement. It can be set in different ways.
System Operation
47
• Never Stop. The system measures continuously. • Soft Key. The system stops measuring when a Soft Key is pressed. This • • • •
key appears on the main screen. Command. The system stops measuring when an external command, PM:TRIG:STOP (Section 8.3.3) is sent via USB. Value. The system stops measuring when the measured signal crosses a user programmed value. Time. The system stops measuring when a user programmed time passed between the Start event and the current measurement. Number of Samples. The system stops measuring when a user programmed number of measurements passed between the Start event and the current measurement.
The Trigger Stop can also be set with an external command PM:TRIG:STOP (Section 8.3.3).
4.6
Wavelength Setting Newport detectors have a calibration module or internal memory which stores the Responsivity versus Wavelength Table. If the Lambda key is pressed, a wavelength screen is displayed with the most common values in nanometers (nm) (see Figure 31 on page 41). The screen has two columns. The left column displays the common wavelength values used in the industry, while the right column has custom values. When the user selects one of the predefined wavelengths in the left column, the 1918-C looks up the wavelength in the responsivity table in the detector calibration module. If that exact value is found, the system will use the corresponding responsivity for that particular wavelength. If the value is not found, the system will calculate the responsivity using interpolation. The right column in the Wavelength screen gives the user the option to set custom wavelengths. To do so, with the Navigation keys bring the cursor on top of one of the numbers. The rightmost Soft key becomes Edit Value. Hit this key to edit the custom number. A white cursor appears on the first digit. Press the Up/Down navigation keys to change the number and the Left/Right keys to move to the next digit. When finished, hit Enter. The new custom wavelength will be stored. Press Esc to return to the main screen
4.7
Display Color In a laboratory environment, and especially when one uses protective eyewear, it may be desirable to change the meter display color to
48
System Operation
accommodate the eyewear color. The instrument has predefined color schemes that can be changed any time (Figure 37).
a. Negative black and white screen
b. Positive black and white screen
c. Red screen
d. Green screen
e. Blue screen
f. Color/Blue screen
Figure 37
Predefined color schemes
To change the display colors first press the Enter/Setup key. This will bring the Setup screen and reconfigure the Soft keys (Figure 38).
Figure 38
Pressing the System soft key will bring a secondary setup screen. Navigate to the Color Selection to change the screen color (Figure 39). Also, navigate to the Brightness field and hit Enter to change the screen brightness. The default value is 100%. Press the Measure soft key to go back to the Measurement Settings screen, or press ESC to go back to the main screen.
Figure 39
Setup screen
System Settings screen
System Operation
49
Pressing the About soft key will bring a another screen with information about the unit Firmware version, serial number, calibration date. In addition, the attached detectors data is diplayed (Figure 40). From here, one can navigate back to the Measurement Settings or back to the System Settings. Figure 40 About screen
4.8
USB Address The USB Address can be changed in the System Settings screen (Figure 39). Navigate to the USB Address and hit Enter. In the drop-down menu select the desired USB address.
4.9
Statistics The 1918-C can display statistics for the measurement in progress. From the main screen press the Soft key labeled Statistics. The Statistics screen is displayed as in Figure 41. The left column shows the statistics current setup. The Statistics function has two modes: Fixed and Continuous.
Figure 41
Statistics screen
When in Fixed mode the Statistics engine calculates the minimum (Min), maximum (Max), Range, Mean, Standard Deviation (Std. Dev.) for a fixed number of samples and displays them in the right column. The number of samples is displayed in the left column on the Samples line. As Figure 41 shows, the number of samples is 10000 with a time interval between samples of 100 µs. This means that the statistics values are calculated over 1 second interval. If the Mode is Fixed, at the end of the 10000 samples, the statistics values are cleared and the calculation starts again with the next measurement. The user can change the Mode with the Navigation keys. When the Enter key is pressed a drop-down menu allows the user to select Fixed or Continuous Mode. By using the Up and Down navigation keys followed by Enter, the user can change the Mode to Continuous. In Continuous Mode the statistics calculations are done over the same
50
System Operation
number of samples, 10000, but these samples are updated in real time in a first-in-first-out (FIFO) fashion. The system starts filling up the list of 10000 and calculates the statistics with the available number of samples at hand. When the list is filled, as the next sample comes, the system drops the first measurement in the list, number 1, shifts the entire list down, and places the next measurement on the 10000 level. The statistics are recalculated for the new list and the process repeats with the new measurement. The Soft keys offer the user the option to clear the statistics at any time, with Clear Stats soft key, and to return back to the default screen with Display OFF soft key. The Graph soft key (Section 4.9.1) can be used for the visualization of the measured values on a time graph. The Statistics screen displays also the current measured value at the top of the right column.
4.9.1
Graph The Graph soft key displays the last 10000 measurements on a time graph (Figure 42). Due to the sample time interval of 100µs, the graph duration is 1 second. The graph width is 270 pixels and, because of that, the system has to decimate the 10000 samples to fit them in this fixed number of pixels. Therefore, the graph might look choppy if the graph zoom is set on 1.
Figure 42
Graph screen
The user can zoom into the graph with the Soft keys +Zoom and –Zoom. As the zoom changes the graph displays a finer picture of the measurements. The zoom value is retained at the top of the screen. Pressing the +Zoom soft key will zoom in the graph 2 times the previous zoom value. Pressing the – Zoom soft key will zoom out ½ times the previous zoom value. The maximum graph value is displayed in the upper left corner of the display. If the Cursor soft key is pressed, a vertical line (cursor) is displayed. The user can direct the cursor left or right with the Navigation Keys to read the measured values on the graph. The current value is displayed in the upper right corner and marked on the screen with a red dot.
System Operation
4.10
51
Math Functions The Math function is displayed on the math field, at the upper right corner, (Figure 43). To display the Math field the user selects the soft key labeled Math in the main screen. This in turn displays the math configuration screen The Math function can be used to add, subtract, multiply or divide the current measurement Ch. A with a reference Ref. A in real time. Once in the Math configuration screen the user can use the Navigation keys to build the mathematical expression. From the first column the user can select the first variable in the expression, from the second column, the operator, and from the third column, the second variable. When the selection was made, the system returns to the main screen after the Enter key was pressed.
Figure 43
Figure 44
Math field
Math configuration screen
The Ref. value is assigned a default value of 1 when the system is first turned on. The reference value is stored and displayed in the selected units. The user can change the reference value with a remote command PM:REF:VAL value as described in Section 8.3. If the displayed units change, then the user needs to update the stored reference value so that the system will store the new units in the reference. The Math field can be turned off from the math configurations screen. The second Soft key is labeled Display OFF. If this key is pressed the system returns to the default screen and the Math field disappears.
4.11
Measurement Correction Settings The 1936/2936 Series power meters provide users the capability to correct actual measurements taken by it through a “Correction Settings” screen. This screen can be accessed by pressing the “Correction” soft-key in “Measurement Settings” screen (Figure 45). The “Measurement Settings” screen, as described earlier, can be accessed by pressing the Setup key from main measurement screen.
52
System Operation
The Correction Settings screen (Figure 46) allows users to enter two (2) multiplier values, labeled “Multiplier 1” (M1) and “Multiplier 2” (M2), besides an “Offset” value. The corrected measurement is arrived at using the formula shown below: Corrected measurement = [(Actual measurement * M1) – Offset] * M2.
Figure 45
Measurement Settings
Figure 46
Correction Settings
Note that these settings are channel specific, and apply to the primary channel viewed on the main measurement screen. The default value for the two multipliers is 1.0, and the offset is 0.0. If any one of these three parameters are changed from their default values, the main measurement screen shows the corrected measurement. A new field called “Detector:” appears at the bottom of the main screen that displays
4.12
Display Modes The selection of various display modes can be done from the default screen, by pressing the Mode soft key. When the Mode selection screen is displayed (Figure 47), the display mode can be selected from the second column.
Figure 47
Mode selection screen
System Operation
4.12.1
53
Numeric Display The numeric display is the default display of the 1918-C. The numeric display shows the current measured value.
Figure 48
4.12.2
The Numeric display
Analog Bar The Analog Bar display mode brings a bar graph below the numeric display. The bar graph is white and follows the value showed by the numeric display. The minimum and maximum labels displayed just below the bar graph represent the input range the unit is currently set on. For example, if the unit is set on 109.99 µW range, then the bar graph shows the same range of 0 to 109.99 µW. In the middle of the bar graph the displayed number is the middle of the range.
Figure 49
Analog Bar
The major ticks represent 10% of the range, and the minor ticks represent 5% of the range. If the Soft key labeled Show Max is selected, the maximum value is retained and displayed in the bar graph with red color. The red bar is updated with each measurement, if the current measured value is larger than the largest of the previous measurements. Besides the maximum value being displayed with a red bar, the actual value is displayed above the bar graph where “Max=” shows the value. If the Soft key labeled Show Min is selected, the minimum value is retained and displayed in the bar graph with green color. The green bar is updated with each measurement, if the current measured value is smaller than the smallest of the previous measurements. Besides the minimum value being displayed with a green bar, the actual value is displayed above the bar graph where “Min=” shows the value. The maximum and minimum bars can be reset with the Reset m/M soft key.
54
System Operation
For users who would like to fine adjust a maximum or a minimum, the 1918-C offers the Auto Zoom function. When the Auto Zoom soft key is pressed another bar appears above the Analog Bar. The bar length is 2% of the Analog Bar. It is a display of the region around the end of the analog bar. Figure 50
Auto Zoom
The Auto Zoom bar displays with white the current measured value, as the Analog Bar does. However its trip is more sensitive, because the maximum trip is +/-1% of the Analog Bar. If the Show Max or Show Min soft keys are pressed, the system behaves the same as with the Analog Bar, displaying with red the maximum value and with green the minimum value. As an example, as Figure 50 shows, the red bar in the Analog Bar is very small, so with the Analog Zoom this bar is extended giving the user the convenience to see better small signal variations. Pressing the Reset m/M soft key, clears the minimum and maximum bars from both the Analog Bar and the Auto zoom graphs.
4.12.3
Analog Needle The Analog Needle displays a vertical marker that moves with the displayed numeric value. It is useful for users who look for a maximum or a minimum when adjusting the optical power.
Figure 51
Analog Needle display
System Operation
4.12.4
55
Vertical Chart When the Vertical Chart is selected the numeric display is moved in the upper right corner. The vertical chart scrolls down, representing a snapshot of the last measurements. The chart can be cleared with the Clear soft key. The maximum peak value of the chart is the maximum measurement of the entire chart, since the last clear. Below the chart, there is a line with the chart maximum and minimum in major units. On the same line in the middle, there is information about the chart zoom level, e.g. 2x, and the number of samples processed per chart line, e.g. 10 Avg (Figure 52).
Figure 52 Vertical chart with 10 measurements per line
The chart has 100 lines, each line having a white and red color. When the system fills up a line, it looks at a number of samples defined by the number displayed below the chart. Figure 53 Vertical chart with 1 measurement per line
Figure 52 shows 100x -- 10 Avg, which means that, while painting a line, the system looks at the previous 10 measurements. It displays with white the minimum value in the 10- measurement list and with red the maximum value in the same list. The user can change the number of measurements by selecting the Average soft key and then pressing the Right or Left Navigation keys, to increase, respectively decrease the number of measurements. If one measurement is selected, the chart color is white, because the maximum and minimum per line are the same (Figure 53). Due to one measurement display per line, the chart speed increases. If the Zoom soft key is pressed the user can zoom into the chart with the Up and Down Navigation keys
4.13
Optical Meter Firmware Upgrade Procedure Firmware Upgrade is an easy, straight-forward process. Simply copy firmware files (PM1918APP.EXE and XMLFILE1.XML) to a WinCE compatible USB Flash Drive and then plug it into the USB connector on the front of the instrument. Then wait a few seconds for the instrument to recognize the USB Flash Drive. The Optical Meter will detect the new firmware files and will ask if you want to download the files. Press the “Yes”
56
System Operation
softkey to start the upgrade process. The Optical Meter will instruct you to restart once the upgrade is successful. Restart the Optical Meter by turning it OFF and back ON. The Optical Meter will restart running the new firmware. New firmware files may be available either through the Newport web site (http://www.newport.com) at the product page or through your local Newport application specialist.
5
Performing Basic Measurements
5.1
Introduction Many different types of optical measurements are possible using the 1918-C Optical Meter. Most of these possible measurements are selected from within the MODE menu. This chapter discusses these measurements.
5.2
Measurement Modes and Units The 1918-C provides a number of measurement modes for acquiring data. At power on, the meter checks the detector’s calibration EEPROM to determine the available measurement modes supported by the detector. Measurements can be displayed in various units. The detector type and the measurement mode determine the set of units available at any given time. Table 1 illustrates the measurement modes and units available for each detector family. The measurement modes are grouped naturally into three categories: CW, Peak-to-Peak (Pk-Pk), and Pulsed. Each will be discussed in the sections below. The 1918-C sets the measurement to a detector specific default mode depending on the detector used. All Newport detectors have internal logic or calibration modules. Based on the data stored in detectors, the instrument knows to auto configure itself and sets up the mode, range, filter, rate, etc. The user, in the setup screen, can change the detector specific default mode. The basic measurement techniques for using the 1918-C are covered in the following sections. Refer to Table 1 for a review of the 1918-C’s functions and measurement capabilities.
(918DSeries)
HighPower (818PSeries)
dB
REL / %
X
X
X
X
X
X
X
X
X
X
X
X
X
CW Integrate Pk-Pk Continuous Pk-Pk Single CW Continuous CW Single
Energy
CW Integrate Pulse Continuous
(818ESeries)
Pulse Single
X
X
Sun
dBm
X
CW Single
J/cm2
CW Continuous
Mode
J
W/cm2
LowPower
W
Detector Family
A
Performing Basic Measurements
V
58
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Table 1 Available Measurement Modes and Valid Units.
The following instructions assume familiarity with the meter’s functions. They also include steps to incorporate background correction and assume that the experimental setup under-fills and does not saturate or damage the detector.
5.3
CW Measurements (with 918D or 818P Detectors) This section describes the procedure for making basic optical power measurements while properly removing the influence of ambient light and other drift effects.
• With a 918D (also 818-XX lower power detectors with proper adapters) or 818P-Series Detector connected to the meter, turn the meter on. Press the Mode key and then select CW Continuous with the Navigation keys. Use the ESC key to return to the Main screen. Set Range to Auto and press the Lambda (λ) key to set the measurement wavelength to the desired value. • Cover or otherwise block the light source being measured and then press the Zero key to turn the Offset on. This effectively removes any background signal from subsequent measurements. • Uncover the source so that it illuminates the detector and note the displayed value. This reading is the optical power observed by the detector due to the source.
Performing Basic Measurements
59
This process assumes that the ambient signal is not changing between the time when the Zero key is pressed and when the measurement is made. The user should remember that, if he/she can see the detector active area as he/she moves around, then the detector registers this as a changing ambient DC signal!
• For the 918D series detectors (also 818-XX lower power detectors with proper adapters) you can decide whether to use the attenuator for your measurement or deactivate (or physically remove on 818 low power series) the attenuator. a. For very low power measurements, below µW range in various ambient light environments, you can elect to use the detector with no physical attenuator in the optical path. This will increase the sensitivity and hence accuracy of the measurement. b.
In case of higher power measurement, the attenuator should be used to avoid damage or saturation of the detector. The attenuator use is recommended in mW to low Wattage range incident power. Please refer to the specifications of the particular detector to make sure you do not exceed the saturation levels of the detector.
For the 918D series detectors with integrated (non-removable) attenuators, there is a switch built into the detector head, sensing the position of the attenuator. The Optical Meter will then automatically use proper calibration data for presence or absence of the attenuator in front of the photo diode. For models such as 818 low power series detectors which have a removable attenuator, there is no switch built into the detector head, hence the user will have to manually select attenuator option status on the meter to obtain the proper power or signal readings.
5.4
Peak-to-Peak Power Measurements (918D Detectors) This section describes the procedure for making basic optical peak-to-peak power measurements.
• With a 918D Low Power Detector connected to the meter, turn the meter on. Set the Mode to Pk-Pk Continuous. Set Range to Auto and press the Lambda (λ) key to set the measurement wavelength to the desired value. • Illuminate the detector and note the displayed value. This reading is the peak-to-peak optical power observed by the detector. • Accurate peak-to-peak power measurements can be made for pulse repetition rates up to 20 kHz.
5.5
Power Ratio and Power Reference measurements This section describes how to use the mathematical functions in the Optical Meter to obtain a power or signal comparison to a previously saved value. The readout can be displayed as a linear ratio, a percentage or in dB. Refer to Section 4.10 for information on setting the reference values.
60
Performing Basic Measurements
• Example 1 – In order to select dB ratio versus a stored reference value: a. While in the Math function screen, select channel A by using the up or down arrow keys. There will remain a black border around the highlighted/selected channel as you leave the column for the next selection. b. Move to the next column by using the right arrow key, and select “/(dB)” option. c. Move to the last column by using the right arrow key and use the up or down keys to select Ref. A. d. Press the Menu/Enter key to accept the selections and exit the Math function screen. e. The result of Ch. A/Ref. A in units of dB will appear in the designated window on the screen.
• Example 2 – In order to get the difference between channel A and a stored reference value: a. From the main screen of the meter, select soft key labeled “Math” to enter the math function screen. If you cannot see the label “Math”, press the “ESC” key. b. Use the direction keys to highlight channel A in the first column c. Using the direction keys, navigate to the “-“ symbol in the center column. d. Using the direction key, move the final column such that Ref. A is highlighted. e. Press the Menu/Enter key to retain the settings and exit the screen at the same time. f. The result of Ch. A- Ref. A will be displayed in the designated window of the main display screen.
5.6
Pulse Energy Measurements (818E Detectors) This section describes the procedure for making basic optical pulse energy measurements.
• With an 818E Energy Detector connected to the meter, turn the meter on. Set the Mode to Pulse Continuous. Set the Range to Manual Mode and press the Lambda (λ) key to set the measurement wavelength to the desired value. • Illuminate the detector and note the displayed value as the meter measures each laser pulse. These readings represent the energies of the incident laser pulses. The meter will display the last pulse energy measured until a new pulse arrives. • Accurate measurements can be made for pulse repetition rates up to 10 kHz, depending on the limitation of the specific detector in use, of course.
Performing Basic Measurements
61
For Pulse Energy Measurements the Auto Range Mode is disabled. The reason is the fact that the Optical Meter has an advanced engine that allows for Pulse-by-Pulse measurements rather than Pulse Amplitude Averaging. Measuring the laser pulses in pulse by pulse mode gives the user more information about the laser behavior versus averaging. The drawback is that, in Pulse-by-Pulse measurements, there is always a possibility that two or more adjacent pulses fall in between ranges forcing the Optical Meter to try to auto range quickly. The result would be an unreadable display. The user needs to set the Optical Meter range based on a priori knowledge about the signal he measures. The behavior is similar with setting the range on an oscilloscope.
5.7
Signal Integration Measurements (918D or 818P Detectors) This section describes the procedure for making a basic signal integration measurement while properly removing the influence of ambient light and other drift effects. The 1918-C begins and ends the signal integration every second.
• With a 918D or 818P Detector connected to the meter, turn the meter on. Set the Mode to CW Continuous. Set the Range to Auto and press the Lambda (λ) key to set the measurement wavelength to the desired value. • Cover or otherwise block the light source being measured, turn Zero on and then set the Mode to CW Integrate. Immediately upon entering the integration mode, the meter will begin to acquire and integrate data. The display value may reflect the integration of noise due to ambient temperature fluctuations (when using the 818P detectors) or light fluctuations (when using the 918D detectors). • Uncover or trigger the source. The displayed value should now reflect the detector signal integration value.
NOTE This process assumes that ambient signals are not changing between the moments when the user zeros the display and when the measurement is made.
5.8
Measuring Laser Pulse Energy with an 818P Thermopile Detector (Single Shot) This application makes use of the 1918-C’ CW Integrate mode (see Section 5.7 above). When an optical pulse with energy E(λ) is incident on a thermopile (818P Series), a voltage signal is generated at the detector input as the heat pulse flows out to the cooling fins. The sum of a series of integrated signals (each one second long) resulting from this heat pulse is a measure of the optical pulse energy, see Figure 54.
62
Performing Basic Measurements
Figure 54
Measuring Laser Pulse Energy via a Thermopile in CW Integrate Mode
A recommended procedure is:
• With an 818P High Power Detector connected to the meter, turn the meter on. Set the Mode to CW Continuous. Set the Range to Auto and press the Lambda (λ) key to set the measurement wavelength to the desired value. Set Zero on and then change Mode to CW Integrate. • Before the optical pulse arrives, the display may reflect the integral of detector noise due to ambient temperature fluctuations. • Trigger the laser pulse. The display will display a new integrated energy measurement every second. The readings will start decreasing rapidly after the first couple of measurements due to the decline in heat flow from the relatively slow thermopile detector. • When the displayed reading drops again to the point of essentially displaying the detector’s noise component, the individual stored readings may be retrieved via the USB interface. Summing these readings will yield the pulse energy.
NOTE This method works best if the integrated result of the pulse signal is much larger than the integral of the detector’s noise component. If the integrated result of the pulse is not much larger, then error in the measurement will arise due to the uncertainty generated by integration of the noise component terms.
NOTE The time constant of a thermopile detector determines the amount of time that one should expect to wait when making an integrated energy measurement of an optical pulse. Typically, an accurate value will be at 5 time constant after the arrival.
Performing Basic Measurements
5.9
63
RMS Measurements This section describes the procedure for making a basic signal RMS (Root Mean Square) measurement while properly removing the influence of ambient light and other drift effects. The 1918-C begins and ends the signal RMS every second.
• With a 918D or 818P Detector connected to the meter, turn the meter on. Set the Mode to RMS. Set the Range to Auto and press the Lambda (λ) key to set the measurement wavelength to the desired value. • Cover or otherwise block the light source being measured, turn Zero on. Immediately upon entering the RMS mode, the meter will begin to acquire and calculate RMS value of the data. The display value may reflect the RMS of noise due to ambient temperature fluctuations (when using the 818P detectors) or light fluctuations (when using the 918D detectors). • Uncover or trigger the source. The displayed value should now reflect the detector signal RMS value. • The RMS value is calculated based on data acquired over a one second time period. The formula used to calculate the RMS value is given below: n
y=
∑x i =0
2 i
n
Where xi is the signal measured, n is the number of samples acquired over a one second period, and y is the RMS value.
NOTE This process assumes that ambient signals are not changing between the moments when the user zeros the display and when the measurement is made.
64
Performing Basic Measurements
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6
Software Application
6.1
Overview The 1918-C has a USB connector on the side of the unit that is used to connect to a computer for use with this application. (RS-232 connection for this application is not supported.) Provided on the CD that comes with the unit is an installation for this software application, it communicates with the 1918-C using the USB port. The installation installs the USB drivers that are required to use USB communication. The design of the software is to allow the user to remotely control basic functions of the instrument.
6.2
Connection Start the application, which will detect and connect the attached Optical Meter. The 1918-C Optical Meter has just one channel, so channel B is grayed out.
Connect Button / Indicator
Figure 55
Application front panel
66
Software Application
6.3
General Usage This software application allows the user to setup and monitor the instrument remotely. The controls on the instrument are available in the software in a very easy to read and change format.
Figure 56
Application Advanced Options (Configuration Tab)
The application is designed to have menus similar to standard Windows applications like MS Word, to ease usability.
6.4
Menu Structure To Exit the application go to the File menu and select Exit. The Edit/Advanced Options menu has additional property settings, including channel settings and data logging options. The Help/About will show information about the application, including firmware version when an instrument is connected and communicating.
7
Computer Interfacing
7.1
General Guidelines The 1918-C Optical Meter has a USB computer interface port used to send commands to the Optical Meter from a host PC. The connection to a computer is done via a USB cable Type "A" Male Connector to Type "MiniB" Male Connector. The commands supported by the Optical Meter can be divided into the following two categories: commands that cause the Optical Meter to take a desired action, and commands (queries) that return a stored value or state of the Optical Meter. Query commands are always terminated by a question mark (?). It is recommended that when a query command is sent, the response to that command from the Optical Meter be read before issuing any other command. Set commands, on the other hand, are used to configure/setup the Optical Meter for a desired mode of operation. These commands take at least one parameter. The subsequent sections in this chapter detail the USB communication protocols supported by the Optical Meter.
7.2
Computer Interface Terminology Listed below are the key abbreviations and concepts used in the command reference section (Section 8) of this manual.
7.2.1
Delimiting Punctuation For the purposes of this manual, any string enclosed by is considered to be a command, a string or numerical argument. The punctuation is used to symbolize the typographic limits of the command, string or argument in question.
7.2.2
Carriage Return The ASCII encoded byte 13 in decimal. (0D hex)
7.2.3
Line Feed The ASCII encoded byte 10 in decimal. (0A hex)
7.2.4
(;) Semicolons Semicolons are used to separate commands within a single transmission (concatenation).
68
Computer Interfacing
7.2.5
Numerical Types Numerical parameters are passed and returned as the actual ASCII characters in the string representation of the number. See section 12.2 for more detailed information.
7.2.6
String Types See the section 12.1 for a detailed description of .
7.3
USB Communication The instrument is designed to communicate with standard USB interfaces. Before connecting the instrument to the USB interface the user should install the application included in the software CD that accompanies the Optical Meter. The application automatically installs the right USB drivers. Communication can be done through this interface by using the application or by developing software in the user’s preferred programming language. The software CD contains drivers and example programs in the following programming languages: LabVIEW, Visual Basic, and Visual C++.
8
Communication Command Reference
8.1
1918-C Optical Meter Remote Interface Commands A complete listing of the commands supported by the 1918-C Optical Meter is provided below.
8.2
Command Overview There are two types of commands: commands that cause the Optical Meter to take a desired action, and queries that return a stored value or state of the Optical Meter. Queries must end with a question mark (?), while commands may require parameter(s) to follow: PM:Lambda 810 For example, the value “810” in the command PM:Lambda 810 sets the wavelength to 810nm. The table below summarizes all the commands and queries supported by the 1918-C Optical Meter. The command/query MUST contain all of the letters, which are shown in upper case in this table. The lower case letters shown with the commands are optional, and may be used for clarity. If any of the optional letters are used, then all of the optional letters are required for the command. The commands may be sent to the instrument in either upper or lower case or in any combination. For example, the following commands are equal: PM:Lambda 810 PM:L 810 pm:L 810 Pm:L 810 COMMAND EXECUTION: The controller interprets the commands in the order they are received and execute them sequentially. If a set of commands have to be executed closer to each other, these commands can be sent to the controller simultaneously by creating a command string with semicolon (;) used as a command separator. The command string length should not exceed 50 characters. In the example shown below, a command string was created with semicolon
70
Communication Command Reference
separating 5 queries. The controller responds to this command string with a response that has 5 values using a comma (,) as a separator. COMMAND STRING: PM:P?;PM:ATT?;PM:L?;ERR? INSTRUMENT RESPONSE: 1.2450,1,810,0
8.3
Optical Meter Command Description
8.3.1
Command Glossary Root level Commands/Queries Summary
Name
Number of Parameters
*IDN? *RCL *SAV ADDRess ADDRess? ERRors?
NONE 1 1 1 NONE NONE
ERRSTR?
NONE
Function Identification query Recall configuration settings Save configuration settings Sets the instrument’s USB address Returns the instrument’s USB address Returns errors generated since the last query. Returns errors and their corresponding error text generated since the last query.
Table 2
Page No. 73 73 73 74 74 75 75
Root level Commands/Queries Summary
Tree level Commands/Queries Summary Name DISP:BRIGHT DISP:BRIGHT?
Number of Parameters 1 NONE
PM:AC:BackLight
1
PM:AC:BackLight?
NONE
PM:AC:LEVEL
1
PM:AC:LEVEL?
NONE
PM:AC:STANDBY
1
PM:AC:STANDBY?
NONE
PM:ANALOGFILTER PM: ANALOGFILTER? PM:ANALOG:IMP PM:ANALOG:IMP? PM:ANALOG:OUT PM:ANALOG:OUT?
1 NONE 1 NONE 1 NONE
PM:ATT
1
PM:ATT?
NONE
PM:ATTSN? PM:AUTO PM:AUTO?
NONE 1 NONE
Function Sets the backlight level of the display and the keypad Returns the backlight level of the display and the keypad Sets the inactive time duration for reducing the backlight level during AC operation Returns the inactive time duration for reducing the backlight level during AC operation Sets the reduced backlight level following inactive time duration during AC operation Returns the reduced backlight level following inactive time duration during AC operation Sets the inactive time duration for going to standby during AC operation Returns the inactive time duration for going to standby during AC operation Sets the analog filter to desired value Returns the analog filter setting Sets the analog output impedance to desired value Returns the analog output impedance value Sets the analog output range to desired level Returns the analog output range Selects if the attenuator’s calibration data is included for power calculation. Returns setting if attenuator data should or should not be used when calibrating the Optical Meter. Gets the attenuator serial number. Sets the Optical Meter ranging to manual or automatic. Returns 1 if automatic Optical Meter ranging is selected.
Page No. 72 72 75 76 76 77 77 77 78 78 79 79 79 80 80 80 81 81 81
Communication Command Reference Name
Number of Parameters
PM:BAT:BL
1
PM:BAT:BL?
NONE
PM:BAT:LEVEL
1
PM:BAT:LEVEL?
NONE
PM:BAT:STANDBY
1
PM:BAT:STANDBY?
NONE
PM:CALDATE?
NONE
PM:CALTEMP?
NONE
PM:CORR PM:CORR? PM:DETMODEL? PM:DETSIZE? PM:DETSN? PM:DIGITALFILTER PM: DIGITALFILTER? PM:DPower? PM:DS:BUFfer PM:DS:BUFfer? PM:DS:Clear PM:DS:Count? PM:DS:Enable PM:DS:Enable?
3 NONE NONE NONE NONE 1 NONE NONE 1 NONE NONE NONE 1 NONE
PM:DS:GET? PM:DS:INTerval PM:DS:INTerval? PM:DS:SAVEBUFER PM:DS:SIZE PM:DS:SIZE? PM:DS:UNITs?
1 1 NONE 1 1 NONE NONE
PM:FILTer
1
PM:FILTer?
NONE
PM:Lambda PM:Lambda? PM:MAX:Lambda? PM:MAX:Power? PM:MIN:Lambda? PM:MIN:Power? PM:MEAS:TIMEOUT PM:MEAS:TIMEOUT? PM:MODE PM:MODE? PM:Power? PM:PWS?
1 NONE NONE NONE NONE NONE 1 NONE 1 NONE NONE NONE
PM:RANge PM:RANge? PM:REF:VALue
1 NONE 1
71 Function
Sets the inactive time duration for reducing the backlight level during battery operation Returns the inactive time duration for reducing the backlight level during battery operation Sets the reduced backlight level following inactive time duration during battery operation Returns the reduced backlight level following inactive time duration during battery operation Sets the inactive time duration for going to standby during battery operation Returns the inactive time duration for going to standby during battery operation Returns the calibration date of the detector. Returns the temperature at which the calibration was performed. Sets the power measurement correction settings. Power measurement correction settings query Returns the model number of the detector. Returns the detector surface area Returns the serial number of the detector. Sets the digital filter to desired value Returns the digital filter setting Detector Power query Set data store behavior select. Returns data store behavior select. Clear data store. Returns data store count of items stored. Set data store enable. Returns data store enable. Returns data store data. {1,1-10,-5,+5} – value, range, oldest 5, newest 5 Set data store interval. Returns data store interval. Saves the data store buffer to a WinCE compatible USB flash disk Sets the size of the Data Store buffer Returns the sizes of the Data Store buffer Returns data store units. Selects the filtering operation: no filtering, analog filter, digital filter, or analog and digital. Returns the filtering operation: no filtering, analog filter, digital filter, or analog and digital. Sets the wavelength for use when calculating power. Gets the selected wavelength in nanometers. Returns the longest calibrated wavelength in nanometers. Returns the maximum readable power in present range Returns the shortest calibrated wavelength in nanometers. Returns the minimum readable power in present range Sets the measurement timeout period Returns the measurement timeout period Acquisition mode select Returns the currently selected acquisition mode. Returns the power in the selected units. Returns the power with status. Selects the gain stage when making readings with the detector head within a range from 0 to 6 (with zero being the highest). Returns an integer indicating the current range. Sets the user reference value for use in relative or dB readings.
Page No. 81 82 82 83 83 84 84 84 85 85 85 86 86 86 86 87 87 87 88 88 88 88 89 89 89 89 90 90 91 91 91 92 92 92 93 93 93 93 94 94 95 95 95 96 97 103
72
Communication Command Reference Number of Parameters NONE
Name PM:REF:VALue? PM:REF:STOre
NONE
PM:RESPonsivity?
NONE
PM:RUN PM:RUN? PM:SPOTSIZE PM:SPOTSIZE? PM:STAT:MAX? PM:STAT:MEAN? PM:STAT:MIN? PM:STAT:MAXMIN? PM:STAT:SDEViation? PM:Temp? PM:TRIG:START PM:TRIG:START? PM:TRIG:STOP PM:TRIG:STOP? PM:TRIG:STATE PM:TRIG:STATE? PM:UNITs PM:UNITs? PM:ZEROSTOre PM:ZEROVALue PM:ZEROVALue?
1 NONE 1 NONE NONE NONE NONE NONE NONE NONE 1 NONE 1 NONE 1 NONE 1 NONE NONE 1 NONE
Function Returns the user reference value. Sets the user reference value for use in relative or dB readings as the present reading. Gets the responsivity currently used for making power calculations. Disables or enables the acquisition of data. Returns the present acquisition mode. Sets the detector spot size Returns the detector spot size Returns statistics buffer maximum value. Returns statistics buffer mean value. Returns statistics buffer minimum value. Returns statistics buffer maximum-minimum value. Returns statistics buffer standard deviation value. Returns the 918 detector's temperature in degrees Celsius. Set the optional start event Returns optional start event Set the optional stop event Returns optional start event Set the trigger state Returns the trigger state Selects the units for readings. Returns an integer indicating the selected units. Sets the zeroing value with the present reading. Sets the zeroing value. Gets the zeroing value.
Table 3
Page No. 97 97 97 98 98 99 99 99 99 100 100 100 100 101 101 101 102 102 102 102 103 103 104 104
Tree Level Commands/Queries Summary
8.3.2
Display Commands
8.3.2.1
DISP:BRIGHT Description Display brightness command Syntax
BRIGHT brightness
Remarks
The BRIGHT command controls the brightness of the instrument display.
Argument
Type
Description
Brightness
int
Brightness, in levels from 0 to 7
Related Commands: DISP:BRIGHT? 8.3.2.2
DISP:BRIGHT? Description Display brightness query Syntax
DISP:BRIGHT?
Remarks
The BRIGHT? query returns the display brightness setting.
Response
Type
Description
Brightness
int
Display brightness, in levels from 0 to 7
Related Commands: DISP:BRIGHT
Communication Command Reference
73
8.3.3
Optical Meter Commands
8.3.3.1
*IDN? Description
Identification Query
Syntax
*IDN?
Parameters
None
Function Remarks This query will cause the Optical Meter to return an identification string. Model name
Firmware version #
Firmware date
Controller Serial #
NEWPORT XXXX vYYY mm/dd/yy SNZZZZ Examples: NEWPORT 1918-C v2.0.0 11/07/06 SN0001
8.3.3.2
*RCL Description
Recall Configuration Settings
Syntax
*RCL bin
Remarks
The *RCL command restores the power meter to the setup state saved in its non-volatile flash memory.
Argument
Value
Description
bin
0
Reserved
1 to 5
Valid configuration settings
Related Commands: 8.3.3.3
*SAV
*SAV Description
Save Configuration Settings
Syntax
*SAV bin
Remarks
The *SAV command saves the present state of the power meter in its non-volatile flash memory. A particular state is then recalled using the *RCL command. If any one of these parameters are changed, the present state of the power meter will automatically be saved in configuration setting #1. When the power meter is reset, the state of the meter defaults to configuration setting #1. The setup parameters saved include: Display brightness level USB address
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Communication Command Reference
Color scheme Measurement display mode Custom wavelengths AC backlight level AC backlight power AC standby Battery backlight level Battery backlight power Battery standby Argument
Value
Description
bin
0
Reserved
1 to 5
Valid configuration settings
Related Commands: 8.3.3.4
ADDRess Description
USB address command.
Syntax
ADDRess value
Remarks
The ADDRess command sets the Optical Meter USB address. After changing USB address, the communication with the Optical Meter has to be re-initialized.
Argument
Value
Description
Value
0
Reserved
1 to 31
Valid USB address range
Related Commands: 8.3.3.5
*RCL
ADDRess?
ADDRess? Description
USB address query.
Syntax
ADDRess?
Remarks
The ADDRess query returns the Optical Meter’s USB address.
Response
Value
address
0 1 to 31 Related Commands:
Description Reserved Valid USB address range ADDRess
Communication Command Reference
8.3.3.6
75
ERRors? Description
Error query
Syntax
ERRors?
Remarks
The ERRors? query returns a single error number that has occurred since the last query. This error is indicated by a number that corresponds to the type of error that occurred. This command also clears the read error from the Error buffer .
Response
Type
Description
Error code
int
Error code number per Appendix B, 0 if no errors
Related Commands: ERRSTR? 8.3.3.7
ERRSTR? Description
Error string query
Syntax
ERRSTR?
Remarks
The ERRSTR? query returns a single error number along with the corresponding error text string that have occurred since the last error query.
Response Error code,
Type string
Related Commands: 8.3.3.8
Description Error code number and text for error code as"text"per Appendix B, 0 if no errors ERRors?
PM:AC:BackLight Description Inactive time period for reducing the backlight level during AC operation Syntax
PM:AC:BackLight value
Remarks
If the instrument is on AC power, its display backlight will be reduced to a pre-specified level following a period of inactivity specified using this command. The instrument is considered to be inactive if either the keys on the front panel are not being pressed or if there is no communication with a host PC over USB interface.
Argument
Value
Inactive Time Period
Value
0 1 2
1 min 5 min 30 min
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Communication Command Reference
3 2 hours 4 Always Related Commands: PM:AC:BackLight?; PM:AC:LEVEL? 8.3.3.9
PM:AC:BackLight? Description Inactive time period for reducing the backlight level during AC operation Syntax
PM:AC:BackLight?
Remarks
The PM:AC:BackLight? query returns an integer indicating the present inactive time period for reducing the backlight level during AC operation.
Argument
Value
Inactive Time Period
0 1 min 1 5 min 2 30 min 3 2 hours 4 Always Related Commands: PM:AC:BackLight; PM:AC:LEVEL Value
8.3.3.10
PM:AC:LEVEL Description Display backlight level following an inactive time period during AC operation Syntax
PM:AC:LEVEL value
Remarks
If the instrument is on AC power, its display backlight will be reduced following a pre-specified period of inactivity to the level specified using this command. The instrument is considered to be inactive if either the keys on the front panel are not being pressed or if there is no communication with a host PC over USB interface.
Argument
Value
Backlight Level
0 100% 1 75% 2 50% 3 25% 4 OFF Related Commands: PM:AC:BackLight?; PM:AC:LEVEL? Value
Communication Command Reference
8.3.3.11
77
PM:AC:LEVEL? Description Display backlight level following an inactive time period during AC operation Syntax
PM:AC:LEVEL?
Remarks
The PM:AC:LEVEL? query returns an integer indicating the display backlight level following an inactive time period during AC operation.
Argument
Value
Backlight Level
0 100% 1 75% 2 50% 3 25% 4 OFF Related Commands: PM:AC:BackLight; PM:AC:LEVEL Value
8.3.3.12
PM:AC:STANDBY Description Inactive time period for putting the instrument in standby mode during AC operation Syntax
PM:AC:STANDBY value
Remarks
If the instrument is on AC power, it will be put in standby mode following a period of inactivity specified using this command. The instrument is considered to be inactive if either the keys on the front panel are not being pressed or if there is no communication with a host PC over USB interface.
Argument
Value
Inactive Time Period
0 1 min 1 5 min 2 30 min 3 2 hours 4 Never Related Commands: PM:AC:STANDBY?; PM:AC:LEVEL? Value
8.3.3.13
PM:AC:STANDBY? Description Inactive time period for putting the instrument in standby mode during AC operation Syntax
PM:AC:STANDBY?
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Communication Command Reference
Remarks
The PM:AC:STANDBY? query returns an integer indicating the present inactive time period for putting the instrument in standby mode during AC operation.
Argument
Value
Inactive Time Period
0 1 min 1 5 min 2 30 min 3 2 hours 4 NEVER Related Commands: PM:AC:STANDBY; PM:AC:LEVEL Value
8.3.3.14
PM:ANALOGFILTER Description Analog filter select command Syntax
PM:ANALOGFILTER value
Remarks
The PM:ANALOGFILTER command selects the analog filter setting.
Argument
Value
Analog Filter
0 None 1 250 kHz 2 12.5 kHz 3 1 kHz 4 5 Hz Related Commands: PM:ANALOGFILTER? Value
8.3.3.15
PM: ANALOGFILTER? Description Analog filter query Syntax
PM:ANALOGFILTER?
Remarks
The PM:ANALOGFILTER? query returns an integer indicating the present analog filter setting.
Argument
Value
Analog Filter
0 None 1 250 kHz 2 12.5 kHz 3 1 kHz 4 5 Hz Related Commands: PM:ANALOGFILTER Value
Communication Command Reference
8.3.3.16
PM:ANALOG:IMP Description Analog output impedance select command Syntax
PM:ANALOG:IMP value
Remarks
The PM:ANALOG:IMP command selects the analog output impedance.
Argument
Value
Output Impedance
0 50 Ω 1 100 kΩ 2 1 MΩ Related Commands: PM:ANALOG:IMP? Value
8.3.3.17
PM:ANALOG:IMP? Description Analog output impedance query Syntax
PM:ANALOG:IMP?
Remarks
The PM:ANALOG:IMP? query returns an integer indicating the present analog output impedance.
Argument
Value
Output Impedance
0 50 Ω 1 100 kΩ 2 1 MΩ Related Commands: PM:ANALOG:IMP Value
8.3.3.18
PM:ANALOG:OUT Description Analog output range select command Syntax
PM:ANALOG:OUT range
Remarks
The PM:ANALOG:OUT command selects the analog output range.
Argument
Value
Max. Output
0 1V 1 2V 2 5V 3 Reserved Related Commands: PM:ANALOG:OUT? Range
79
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Communication Command Reference
8.3.3.19
PM:ANALOG:OUT? Description Analog output range query Syntax
PM:ANALOG:OUT?
Remarks
The PM:ANALOG:OUT? query returns an integer indicating the present analog output range.
Response
Value
Max. Output
0 1V 1 2V 2 5V 3 Reserved Related Commands: PM:ANALOG:OUT Range
8.3.3.20
PM:ATT Description
Attenuator enable command
Syntax
PM:ATT enable
Remarks
Indicates whether or not the attenuator for the 818 Series power detector is on the detector.
Argument
Type
Description
Enable use of detector responsivity with attenuator available in the calibration module for 818 detectors. Related Commands: PM:ATT? 8.3.3.21
Enable
int
PM:ATT? Description
Attenuator enable query
Syntax
PM:ATT?
Remarks
The PM:ATT? query returns 1 when using attenuator calibration, 0 when calculating power without attenuator data.
Response
Value
attenuator
Description
0 Calibrating power without attenuator 1 Calibrating power using attenuator Related Commands: PM:ATT
Communication Command Reference
8.3.3.22
PM:ATTSN? Description
Attenuator serial number query
Syntax
PM:ATTSN?
Remarks
The PM:ATTSN? query returns the serial number of the attenuator. When no detector is found the Optical Meter responds with "no detector".
Response
Type
Description
serial number
string
Serial number of the attenuator
81
Related Commands: PM:DETMODEL?, PM:DETSN? 8.3.3.23
PM:AUTO Description
Auto range enable command
Syntax
PM:AUTO mode
Remarks
The PM:AUTO command sets the power ranging to either manual or automatic.
Argument
Value
Description
0 Manual Optical Meter ranging 1 Automatic Optical Meter ranging Related Commands: PM:AUTO?, PM:RANge mode
8.3.3.24
PM:AUTO? Description
Auto range mode query
Syntax
PM:AUTO?
Remarks
The PM:AUTO? query returns a value to indicate if auto ranging is enabled or not.
Response
Value
Description
0 Manual Optical Meter ranging 1 Automatic Optical Meter ranging Related Commands: PM:AUTO, PM:RANG mode
8.3.3.25
PM:BAT:BackLight Description Inactive time period for reducing the backlight level during battery operation Syntax
PM:BAT:BackLight value
Remarks
If the instrument is on battery power, its display backlight will be reduced to a pre-specified level following a period of inactivity specified using this command. The instrument
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Communication Command Reference
is considered to be inactive if either the keys on the front panel are not being pressed or if there is no communication with a host PC over USB interface. Argument
Value
Inactive Time Period
0 1 min 1 5 min 2 30 min 3 2 hours 4 Always Related Commands: PM:BAT:BackLight?; PM:BAT:LEVEL Value
8.3.3.26
PM:BAT:BackLight? Description Inactive time period for reducing the backlight level during battery operation. Syntax
PM:BAT:BackLight?
Remarks
The PM:BAT:BackLight? query returns an integer indicating the present inactive time period for reducing the backlight level during battery operation.
Argument
Value
Inactive Time Period
0 1 min 1 5 min 2 30 min 3 2 hours 4 Always Related Commands: PM:BAT:BackLight; PM:BAT:LEVEL Value
8.3.3.27
PM:BAT:LEVEL Description Display backlight level following an inactive time period during battery operation Syntax
PM:BAT:LEVEL value
Remarks
If the instrument is on battery power, its display backlight will be reduced following a pre-specified period of inactivity to the level specified using this command. The instrument is considered to be inactive if either the keys on the front panel are not being pressed or if there is no communication with a host PC over USB interface.
Argument
Value
Backlight Level
Value
0 1 2 3
100% 75% 50% 25%
Communication Command Reference
83
4 OFF Related Commands: PM:BAT:BackLight?; PM:BAT:LEVEL? 8.3.3.28
PM:BAT:LEVEL? Description Display backlight level following an inactive time period during battery operation Syntax
PM:BAT:LEVEL?
Remarks
The PM:BAT:LEVEL? query returns an integer indicating the display backlight level following an inactive time period during battery operation.
Argument
Value
Backlight Level
0 100% 1 75% 2 50% 3 25% 4 OFF Related Commands: PM:BAT:BackLight; PM:BAT:LEVEL Value
8.3.3.29
PM:BAT:STANDBY Description Inactive time period for putting the instrument in standby mode during battery operation Syntax
PM:BAT:STANDBY value
Remarks
If the instrument is on battery power, it will be put in standby mode following a period of inactivity specified using this command. The instrument is considered to be inactive if either the keys on the front panel are not being pressed or if there is no communication with a host PC over USB interface.
Argument
Value
Inactive Time Period
0 1 min 1 5 min 2 30 min 3 2 hours 4 Never Related Commands: PM:BAT:STANDBY?; PM:BAT:LEVEL? Value
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Communication Command Reference
8.3.3.30
PM:BAT:STANDBY? Description Inactive time period for putting the instrument in standby mode during battery operation Syntax
PM:BAT:STANDBY?
Remarks
The PM:BAT:STANDBY? query returns an integer indicating the present inactive time period for putting the instrument in standby mode during battery operation.
Argument
Value
Inactive Time Period
0 1 min 1 5 min 2 30 min 3 2 hours 4 NEVER Related Commands: PM:BAT:STANDBY; PM:BAT:LEVEL Value
8.3.3.31
8.3.3.32
PM:CALDATE? Description Detector calibration date query Syntax
PM:CALDATE?
Remarks
The PM:CALDATE? query returns the calibration date of the detector.
For example:
21JUN1999.
Response
Type
Description
Date
string
DDMMMYYYYY
PM:CALTEMP? Description Temperature at which detector was calibrated query Syntax
PM:CALTEMP?
Remarks
The PM:CALTEMP? query returns the temperature (degrees Celsius) at which the detector was calibrated. When no detector is present, "no detector" is returned.
Response
Type
Description
temperature
float
Returns the temperature at which the detector was calibrated.
Communication Command Reference
8.3.3.33
PM:CORR Description
Power measurement correction settings
Syntax
PM:CORR value1, value2, value3
Remarks
The PM:CORR command sets the power measurement correction settings. These settings are used by the power meter to correct the actual power measurement. The corrected power is calculated using the formula provided below:
85
Corrected Measurement = ((Actual Measurement * value1) + value2) * value3 Argument
Type
Description
value1
float
Multiplier 1 (default = 1.000)
value2
float
Offset (default = 0.000)
value3
float
Multiplier 2 (default = 1.000)
Related Commands: PM:CORR?, PM:Power?, PM:DPower? 8.3.3.34
PM:CORR? Description
Power measurement correction settings query
Syntax
PM:CORR?
Remarks
The PM:CORR? command returns the power measurement correction settings. These settings are used by the power meter to correct the actual power measurement. The corrected power is calculated using the formula provided below: Corrected Measurement = ((Actual Measurement * value1) + value2) * value3
Response
Type
Description
value1
float
Multiplier 1 (default = 1.000)
value2
float
Offset (default = 0.000)
value3
float
Multiplier 2 (default = 1.000)
Related Commands: PM:CORR, PM:Power?, PM:DPower? 8.3.3.35
PM:DETMODEL? Description Detector model query Syntax
PM:DETMODEL?
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Communication Command Reference
8.3.3.36
8.3.3.37
8.3.3.38
Remarks
The PM:DETMODEL? query returns the model number of the detector.
For example:
818-SL.
Response
Type
Description
model
string
Detector model number
PM:DETSIZE? Description Detector surface area Syntax
PM:DETSIZE?
Remarks
The PM:DETSIZE? query returns the surface area of the detector in cm2.
Response
Type
Description
Area
float
Detector surface area
PM:DETSN? Description
Detector serial number query
Syntax
PM:DETSN?
Remarks
The PM:DETSN? query returns the serial number of the detector.
For example:
0001
Response
Type
Description
serial number
string
Detector serial number
PM:DIGITALFILTER Description Digital filter select command Syntax
PM:DIGITALFILTER value
Remarks
The PM:DIGITALFILTER command specifies the digital filter setting.
Argument
Type
Description
Value
int
digital filter size between 0 and 10000
Related Commands: PM:DIGITALFILTER? 8.3.3.39
PM:DIGITALFILTER? Description Digital filter query Syntax
PM:DIGITALFILTER?
Communication Command Reference
Remarks
The PM:DIGITALFILTER? query returns the present digital filter setting.
Argument
Type
87
Description
Value int digital filter size between 0 and 10000 Related Commands: PM:DIGITALFILTER 8.3.3.40
PM:DPower? Description
Detector power query
Syntax
PM:DPower?
Remarks
The PM:DPower? returns the actual power measurement. This measurement does not include any correction settings specified using “PM:CORR” command. When the correction settings are set to default values, the power measurement returned by this command is same as the measurement returned by “PM:P?” command.
Response
Type
Description
Power
float
Power in Watts
Related Commands: PM:Power? 8.3.3.41
PM:DS:BUFfer Description Data Store buffer behavior selection Syntax
PM:DS:BUFfer behavior
Remarks
The PM:DS:BUFfer command selects the behavior mode for control of the Data Store buffer.
Argument
Value
Description
Mode
0
Fixed Size
1
Ring Buffer
The behavior of the ring buffer is to allow continual data collection after the buffer is full where the oldest values will be overwritten when new measurements are taken. Related Commands: PM:DS:BUFfer? 8.3.3.42
PM:DS:BUFfer? Description Data Store buffer behavior selection query Syntax
PM:DS:BUFfer?
Remarks
The PM:DS:BUFfer? query returns the value of the Data Store buffer behavior.
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Communication Command Reference
8.3.3.43
8.3.3.44
Argument
Type
Description
Behavior
int
See PM:DS:BUFfer for a definition of the behavior status.
PM:DS:CLear Description Clear the Data Store of all data Syntax
PM:DS:CLear
Remarks
The PM:DS:CLear command resets the data store to be empty with no values.
Argument
Type
none
-
PM:DS: Count? Description Data Store data item count query Syntax
PM:DS:Count?
Remarks
The PM:DS:Count? query returns the number of measurements that have been collected in the Data Store.
Argument
Type
Description
int
The number of measurements that have been collected.
count
8.3.3.45
Description
PM:DS:ENable Description Enable Data Store Collection Syntax
PM:DS:ENable enable
Remarks
The PM:DS:ENable enables or disables the collection of measurements in the Data Store.
Argument
Value
Description
0 Disabled 1 Enabled Data will be collected after the PM:DS:ENable command has been called with a parameter of 1. Data collection will stop when the PM:DS:ENable command has been called with a parameter of 0 or when a fixed size data buffer is full. enable
Related Commands: PM:DS:ENable? 8.3.3.46
PM:DS:ENable? Description Enable Data Store Collection query Syntax
PM:DS:ENable?
Communication Command Reference
8.3.3.47
Remarks
The PM:DS:ENable? query returns the enabled status of the Data Store.
Argument
Type
Description
enable
int
See PM:DS:Enable for a description of the enable argument
89
PM:DS:GET? Description Retrieve Data Store data query Syntax
PM:DS:GET? num
Remarks
The PM:DS:GET? command returns a number of measurements that have been collected in the Data Store.
Argument
Type
Description
“1” – returns the single value specified “1-10” – returns values in the range from 1-10 “-5” – returns the oldest 5 values (same as 1-5) “+5” – returns the newest 5 values Note: depending on the number of data points requested, there may be several read operations required on the USB interface. selection
8.3.3.48
string
PM:DS:INTerval Description Data Store Interval Select Syntax
PM:DS:INTerval
Parameters The parameter is of type that is an integer. The parameter represents the interval in milliseconds for storing one measurement in the data buffer. Function This command sets the interval in milliseconds to be used for data storing. For example if DSINT = 100 and DSSIZE = 100 it will take 100 x 100ms to fill the buffer. Related Commands: PM:DS:SIZE,PM:DS:SIZE?,PM:DS:INTerval? 8.3.3.49
PM:DS:INTerval? Description Data Store Interval Query Syntax
PM:DS:INTerval?
Parameters
None
Function This query returns the interval in milliseconds currently used for data storing.
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Communication Command Reference
Related Commands: PM:DS:SIZE,PM:DS:SIZE?,PM:DS:INTerval 8.3.3.50
8.3.3.51
PM:DS:SAVEBUFFER Description Save the current Data Store data to a file Syntax
PM:DS:SAVEBUFFER filename
Remarks
The PM:DS:SAVEBUFFER command saves the current user Data Store to a file on the WinCE compatible USB Flash Disk plugged into the USB Host port on the front of the Optical Meter.
Argument
Type
Description
Filename
string
The filename that will be created or overwritten on the USB Flash Disk containing the measurments stored in the Data Store.
PM:DS:SIZE Description
Size of the Data Store query
Syntax
PM:DS:SIZE
Parameters The parameter is of type in the range 1 to 250000.The parameter represents the size of the data buffer to be used for data storing. Function This command sets the size of the buffer used for data storing.
NOTE The data buffer is cleared automatically when this command is used and all previously stored data will be gone.
Related Commands: PM:DS:SIZE?,PM:DS:INTerval,PM:DS:INTerval? 8.3.3.52
PM:DS:SIZE? Description Data Store Buffer Size Query Syntax
PM:DS:SIZE?
Parameters
None
Function
This query returns the data store buffer size.
Returns
is of type and represents an integer of the range 1 to 250000.
Related Commands: PM:DS:SIZE,PM:DS:INTerval,PM:DS:INTerval?
Communication Command Reference
8.3.3.53
91
PM:DS:UNITs? Description Data store units query Syntax
PM:DS:UNITS?
Remarks
The PM:DS:UNITS? query returns an integer indicating the units selected.
Response
Value
Description
0 Amps 1 Volts 2 Watts 3 Watts/cm2 4 Joules 5 Joules/cm2 6 dBm 7-10 Reserved 11 Sun Related Commands: PM:UNITS,PM:UNITS? units
Note: The UNITs selection depends on the detector used. Refer to Table 1 for the relationship between the detector type and units. 8.3.3.54
PM:FILTer Description
Filter select command
Syntax
PM:FILT filter type
Remarks
The PM:FILT command select the filtering operation to be performed on power readings.
Argument
Value
Description
0 No filtering 1 Analog filter 2 Digital filter 3 Analog and Digital filter Related Commands: PM:FILT? Filter type
8.3.3.55
PM:FILTer? Description
Filter type query
Syntax
PM:FILT?
Remarks
The PM:FILT? query returns an integer indicating the present filter mode.
Response
Value
Description
Filter type
0 1
No filtering Analog filter
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Communication Command Reference
2 Digital filter 3 Analog and Digital filter Related Commands: PM:FILT 8.3.3.56
PM:Lambda Description
Wavelength set command
Syntax
PM:Lambda value
Remarks
The PM:Lambda command selects the wavelength to use when calculating power. The value must fall within the calibrated wavelength of the detector.
Argument
Type
Description
Value
int
Wavelength in nanometers (nm)
Related Commands: PM:Lambda?, PM:MAX:Lambda?, PM:MIN:Lambda? 8.3.3.57
PM:Lambda? Description Wavelength query Syntax
PM:Lambda?
Remarks
The PM:Lambda? query returns the selected wavelength in nanometers. This is the wavelength used to look up the responsivity from the calibration data.
Response
Type
Description
Wavelength
int
Wavelength in nanometers (nm)
Related Commands: PM:Lambda, PM:MAX:Lambda?, PM:MIN:Lambda? 8.3.3.58
PM:MAX:Lambda? Description Maximum wavelength query Syntax
PM:MAX:Lambda?
Remarks
The PM:MAX:Lambda? query returns the longest calibrated wavelength in nanometers. If no detector is preset, the max lambda for the last read detector is returned.
Response
Type
Description
Wavelength
int
Wavelength in nanometers (nm)
Related Commands: PM:MIN:Lambda?
Communication Command Reference
8.3.3.59
8.3.3.60
93
PM:MAX:Power? Description Maximum power query Syntax
PM:MAX:Power?
Remarks
The PM:MAX: Power? returns current range’s maximum readable power.
Response
Type
Description
Power
float
Power in Watts
PM:MIN:Lambda? Description Minimum wavelength query Syntax
PM:MIN:Lambda?
Remarks
The PM:MIN:Lambda? query returns the shortest calibrated wavelength in nanometers. If no detector is preset,min lambda for the last read detector is returned.
Response
Type
Description
Wavelength
int
Wavelength in nanometers (nm)
Related Commands: PM:MAX:Lambda? 8.3.3.61
PM:MIN:Power? Description Minimum power query Syntax
PM:MIN:Power?
Remarks
The PM:MIN: Power? returns current range’s minimum readable power.
Response
Type
Description
Power
float
Power in Watts
Related Commands: PM:MAX:Power? 8.3.3.62
PM:MEAS:TIMEOUT Description Measurement timeout set command Syntax
PM:MEAS:TIMEOUT value
Remarks
This command sets the measurement timeout period. This value is used for making the following measurements: 1. Peak-to-peak measurements: These measurements are updated once every timeout period when the power meter is in Peak-Peak Continuous mode.
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Communication Command Reference
2. Auto-ranging in Pulse Continuous mode: The power meter automatically shifts to a lower range once every timeout period when it determines that no pulse measurements could be taken in the existing range. Users must set this timeout value to 250ms or larger than their pulse repetition rate in order to be able to perform measurements accurately. Argument
Type
Description
Value
int
Timeout value (milliseconds)
Related Commands: PM:MEAS:TIMEOUT? 8.3.3.63
PM:MEAS:TIMEOUT? Description Measurement timeout query Syntax
PM:MEAS:TIMEOUT?
Remarks
The PM:MEAS:TIMEOUT? query returns the selected measurement timeout value in milliseconds.
Response
Type
Description
Timeout
int
measurement timeout in milliseconds
Related Commands: PM:MEAS:TIMEOUT 8.3.3.64
PM:MODE Description
Acquisition mode select
Syntax
PM:MODE mode
Remarks The PM:MODE command selects the acquisition mode for acquiring subsequent readings. Argument
Value
Description
0 DC Continuous 1 DC Single 2 Integrate 3 Peak-to-peak Continuous 4 Peak-to-peak Single 5 Pulse Continuous 6 Pulse Single 7 RMS Related Commands: PM:MODE? Mode
Note: The MODE selection depends on the detector used. Refer to Table 1 for the relationship between the detector type and MODE.
Communication Command Reference
8.3.3.65
PM:MODE? Description
Acquisition mode query
Syntax
M:MODE?
Remarks
The PM:MODE? query returns an integer indicating the present acquisition mode.
Response
Value
95
Description
0 DC Continuous 1 DC Single 2 Integrate 3 Peak-to-peak Continuous 4 Peak-to-peak Single 5 Pulse Continuous 6 Pulse Single 7 RMS Related Commands: PM:MODE Mode
Note: The UNITs selection depends on the detector used. Refer to Table 1 for the relationship between the detector type and units. 8.3.3.66
PM:Power? Description
Power query
Syntax
PM:P?
Remarks
The PM:P? query returns the power in the selected units.
Response Type Description power exp Exponential form (i.e. 9.4689E-04) Related Commands: PM:UNITS?, PM:PWS? 8.3.3.67
PM:PWS? Description
Read with status query
Syntax
PM:PWS?
Remarks
The PM:PWS? query returns two values that are comma delimited: The first value is the power reading and the second value is the status. The status should be used to validate the reading. The reading is in units corresponding to the units field in the status word.
Response
Type
Description
Power reading Status
exp int
Power in present units A bitfield in hexadecimal defining the current channel status
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Communication Command Reference
NOTE The bitfield is defined as follows: Bits 10-7 Channel Units. See PM:UNITS? Bits 6-4 Channel Range, See PM:RANge? Bit 3 Detector Present Bit 2 Channel range change status. Indicates if a measurement has been taken while the unit is ranging Bit 1 Detector Saturated (reserved, follows bit 0) Bit 0 Channel overrange. Indicates that the current measurement is overrange for the current channel range
Related Commands: PM:MODE? Example If the query returns the following values 1.862153E-004, 118 then the Power reading is 1.862153E-004 and the Status is the hex value 118 or the binary value 00100011000b. Taking into consideration the bitfield definition, the status is decoded as follows: Bits 10 - 7 6-4 3 2 1 0
8.3.3.68
Binary 0010 001 1 0 0
Decimal 2 1 1 0 0
Function units = Watts range # 1 detector present instrument not ranging during measurement reserved measurement is not over-range
PM:RANge Description
Range select
Syntax
PM:RANge range
Remarks
The PM:RANge command selects the gain stage when making readings from the detector head. The range of this value depends on the detector being used.
Response
Type
Values range from 0 to 5 for Thermopile and Energy detectors or 0 to 4 for Photodiodes (see Section 2.3.2). Related Commands: PM:RANge?, PM:AUTO range
int
Description
Communication Command Reference
8.3.3.69
97
PM:RANge? Description
Range query
Syntax
PM:RANge?
Remarks
The PM:RANge? query returns an integer that indicates the present range. The range of this value depends on the detector being used.
Response
Value
Description
Values range from 0 to 5 for Thermopile and Energy detectors or 0 to 4 for Photodiodes (see Section 2.3.2). Related Commands: PM:RANge, PM:AUTO range
8.3.3.70
0
PM:REF:VALue Description Reference Value Define Syntax
PM:REF:VALue
Parameters The parameter is of type . Function This command provides a means of directly storing a reference value to be used in linear and logarithmic (dB) relative measurements. The units of this value are the current units being used by the instrument. Related Commands: PM:REF:STOre,PM:REF:VALue? 8.3.3.71
PM:REF:VALue? Description Reference Value Query Syntax
PM:REF:VALue?
Parameters
None
Function This query returns the user defined reference value. The units of this value are the current units being used by the instrument. Returns is of type Related Commands: PM:REF:STOre,PM:REF:VALue 8.3.3.72
PM:REF:STOre Description Reference Value Store
98
Communication Command Reference
Syntax
PM:REF:STOre
Parameters
None
Function This command takes the latest reading and stores it as a reference reading to be used when making relative linear and dB measurements. The units of this value are the current units being used by the instrument. Related Commands: PM:REF:VALue,PM:REF:VALue? 8.3.3.73
PM:RESPonsivity? Description Responsivity query Syntax
PM:RESP?
Remarks
The PM:RESP? query returns the responsivity currently used in making power calculations.
Response
Type
Description
Responsivity float Optical Meter responsivity Related Commands: PM:UNITS?, PM:PWS? 8.3.3.74
PM:RUN Description
Run command
Syntax
PM:RUN mode
Remarks
The PM:RUN command disables or enables the acquisition of data.
Argument
Value
Description
0 Stop 1 Run Related Commands: PM:RUN?, PM:MODE? Mode
8.3.3.75
PM:RUN? Description
Run query
Syntax
PM:RUN?
Remarks
The PM:RUN? query returns an integer indicating the present run mode.
Response
Value
Description
Mode
0
Stopped
1
Running
Related Commands: PM:RUN, PM:MODE?
Communication Command Reference
8.3.3.76
99
PM:SPOTSIZE Description Set detector spot size Syntax
PM:SPOTSIZE value
Remarks
This command sets the detector spot size. By default, the spot size is same as a detector’s surface area. This value is used to when measurement units are set to W/cm2, J/cm2 or Sun.
Argument
Type
Description
Value
float
Spot size (cm2)
Related Commands: PM:SPOTSIZE?, PM:DETSIZE? 8.3.3.77
PM:SPOTSIZE? Description Detector spot size query Syntax
PM:SPOTSIZE?
Remarks
The PM:SPOTSIZE? query returns the detector spot size in cm2.
Response
Type
Description
Spot size
float
detector spot size in cm2
Related Commands: PM:SPOTSIZE, PM:DETSIZE? 8.3.3.78
PM:STAT:MAX? Description Statistics Maximum Value Query Syntax
PM:STAT:MAX?
Parameters
None
Function
This query returns the maximum value in the statistics buffer.
Returns
is of type in exponent notation.
8.3.3.79
PM:STAT:MEAN? Description Statistics Mean Value Query Syntax
PM:STAT:MEAN?
Parameters
None
Function
This query returns the mean or average of all the values in the statistics buffer.
Returns
is of type in exponent notation.
100
Communication Command Reference
8.3.3.80
PM:STAT:MIN? Description Statistics Minimum Value Query Syntax
PM:STAT:MIN?
Parameters
None
Function
This query returns the minimum value in the statistics buffer.
Returns
is of type in exponent notation.
8.3.3.81
PM:STAT:MAXMIN? Description Statistics Max-Min Query Syntax
PM:STAT:MAXMIN?
Parameters
None
Function
This query returns the difference between the maximum and minimum readings in the statistics buffer.
Returns
is of type in exponent notation.
8.3.3.82
PM:STAT:SDEViation? Description Statistics Standard Deviation Query Syntax
PM:STAT:SDEViation?
Parameters
None
Function
This query returns the standard deviation of the readings in the statistics buffer.
Returns
is of type in exponent notation.
8.3.3.83
PM:Temp? Description
918 detectors temperature query
Syntax
PM:Temp?
Remarks
The PM:Temp? query returns the 918 detector's temperature as a float in degrees Celsius.
Response
Type
Description
temp
float
Detector temperature in degrees Celsius (°C)
Communication Command Reference
101
Related Commands: PM:ATT? 8.3.3.84
PM:TRIG:START Description This command sets the optional start event. Syntax
PM:TRIG:START option
Parameters The parameter is of type and is an integer from 0 to 3. Argument
Value
Description
option
0
Continuous measurement
1
Reserved
2
Measurement starts when a designated Soft key is pressed
3
Measurement starts when PM:TRIG:STATE 1 command is issued.
Related Commands: PM:TRIG: START? 8.3.3.85
PM:TRIG:START? Description Trigger START Query Syntax
PM:TRIG:START?
Parameters
None
Function This query returns the TRIGGER START condition. Related Commands: PM:TRIG: START 8.3.3.86
PM:TRIG:STOP Description This command sets the optional stop event. Syntax
PM:TRIG:STOP
Parameters The parameter is of type and is an integer from 0 to 6. Argument
Value
Description
option
0
The measurement never stops
1
Reserved
2
Measurement stops when a designated Soft key is pressed
102
Communication Command Reference
3
Measurement stops when PM:TRIG:STATE 0 command is issued.
Related Commands: PM:TRIG: STOP? 8.3.3.87
PM:TRIG:STOP? Description Trigger STOP Query Syntax
PM:TRIG:STOP?
Parameters
None
Function This query returns the TRIGGER STOP condition. Related Commands: PM:TRIG: STOP 8.3.3.88
PM:TRIG:STATE Description This command sets the trigger state Syntax
PM:TRIG:STATE
Parameters The parameter is of type and is an integer 0 or 1. Argument
Value
Description
option
0
Trigger is armed. The system waits for a trigger start event to occur in order to make a measurement.
1
System is triggered and at least one measurement occurred.
Related Commands: PM:TRIG: STATE? 8.3.3.89
PM:TRIG:STATE? Description Trigger STATE Query Syntax
PM:TRIG:STATE?
Parameters
None
Function This query returns the TRIGGER STATE condition. Related Commands: PM:TRIG: STATE 8.3.3.90
PM:UNITs Description
Units select
Communication Command Reference
103
Syntax
PM:UNITS units
Remarks
The PM:UNITS command selects the units for readings.
Argument
Value
Description
0 Amps 1 Volts 2 Watts 3 Watts/cm2 4 Joules 5 Joules/cm2 6 dBm 7-10 Reserved 11 Sun Related Commands: PM:MODE?
units
Note: The UNITs selection depends on the detector used. Refer to Table 1 for the relationship between the detector type and units.
8.3.3.91
PM:UNITs? Description
Units query
Syntax
PM:UNITS?
Remarks
The PM:UNITS? query returns an integer indicating the units selected.
Response
Value
Description
0 Amps 1 Volts 2 Watts 3 Watts/cm2 4 Joules 5 Joules/cm2 6 dBm 7-10 Reserved 11 Sun Related Commands: PM:UNITS units
Note: The UNITs selection depends on the detector used. Refer to Table 1 for the relationship between the detector type and units. 8.3.3.92
PM:ZEROSTOre Description Zero value set command Syntax
PM:ZEROSTO
Remarks
The PM:ZEROSTO command sets the zeroing value with the present reading.
104
Communication Command Reference
Argument
Type
none
-
Description
Related Commands: PM:ZEROVAL? 8.3.3.93
PM:ZEROVALue Description Zero value set command Syntax
PM:ZEROVAL value
Remarks
The PM:ZEROVAL command sets the zeroing value. When enabled, zeroing subtracts the stored zero value from readings before making measurement calculations.
Argument
Type
Description
Value
float
Zeroing value
Related Commands: PM:ZEROSTO 8.3.3.94
PM:ZEROVALue? Description Zero value query Syntax
PM:ZEROVAL?
Remarks
The PM:ZEROVAL? query returns the zero value.
Response
Type
Description
value
float
Zero exponent
Related Commands: PM:ZEROVAL
9
Principles of Operation
9.1
Introduction The 1918-C Optical Meter electronics adapt to a number of signal measurement tasks: DC current or voltage, AC peak-to-peak current or pulse voltage, or integrated DC current or voltage signals. This versatility is required to handle the various signals that Newport’s Low Power, HighPower, Energy and other detector families generate. These detector families are based on semiconductor, thermopile and pyroelectric. The detector data is introduced to the 1918-C by way of a calibration module specific to the detector in use. At power up (and RESET), the 1918-C downloads information about the detector from the calibration module or the detector internal memory. Based on the calibration module preprogrammed data, the meter learns the set of operating states available to the detector. The user then selects among the available operating states when using the meter. Front panel control and the operating states of the 1918-C Optical Meter are discussed in Section 3.
9.2
Analog Signal Flow The detector signals can follow many different paths through the 1918-C input amplifier chain. A block diagram of analog signal flow is shown in Figure 57. The actual flow path depends upon the detector type and the mode of measurement.
Figure 57
1918-C Optical Meter Analog Signal Flow Diagram
106
Principles of Operation
The analog signal flow path is primarily determined by the responsivity units of the detector. The numerator of these units indicates how the meter must be configured in order to obtain a calibrated optical measurement. Analog signal flow is independent of whether single or continuous measurements are made. Responsivity units and signal flows for the various detector families are listed in Table 4. Detector Family Low-Power Low-Power Low-Power High-Power High-Power Energy
Resp. Units
Mode
A/W A/W A/W V/W V/W V/J
DC Peak-Peak Integral DC Integral Pulse
Table 4
9.3
Amplifier Path I I I V V V
PeakBaseline No No No No No Yes
Analog Signal Flow Paths.
Digitized Signal Flow An analog-to-digital converter captures the input signal. The input signal has the units of current or voltage depending upon how the input amplifier chain was configured. Note: In this manual the digitized signal may be referred as sampled signal or samples. This digitized signal moves through a number of process steps that may or may not alter the digitized value depending upon the operating state of the meter. Each of these possible-processing steps is discussed further. Digital Filter
If the digital filter annunciator Dig or Digital is on, Section 2.3.4, the filter output is the average of the most recent 10, 100, 1000, 10000 samples. The number of samples is selectable by the user with the Filter menu. Also, the user can change the number of samples. When less than the selected number of samples has been acquired since the last reset of the digital filter, the output is the average of all the values received. The digital filter is reset when the 1918-C Optical Meter is turned on and whenever the UNITS or the range changes or when the MODE of operation changes.
NOTE When using the digital filter in CW Single acquisition mode, each measurement is the average of the last 10, 100, 1000, 10000 acquisitions independent of how old any of the measurements are.
Gain
Gain processing accounts for the signal gain of the input amplifiers. The output is the product of the digitized value and the amplifier gain.
Principles of Operation
107
Zero Offset
Zero offset is active whenever the Offset annunciator is lit. The zero offset output is equal to the input value less the zero reference value. Responsivity Map(s)
This process scales the input value in accordance with current calibration wavelength and the responsivity map downloaded from the detector calibration module. The output of this process, i.e. the measurement value, is the digitized input value divided by the responsivity associated with the current calibration wavelength or the user defined calibration value. Different responsivities are used depending upon if the attenuator is on as shown in the Setup Menu. Units Correction
Unit’s correction adjusts a measurement value to account for the display units selected. When the display units are equal to the detector signal units, i.e. equal to the numerator of the responsivity units, Table 1, the measurement value is not adjusted. Otherwise the digitized value is adjusted to account for detector responsivity and/or additional unit conversions such as W-to-W/cm2.
NOTE Per area unit conversions such as W-to-W/cm2 divide the measurement value by the active area of the detector. This calculation assumes that the entire active area of the detector is uniformly illuminated. Per area measurements where the entire detector active area is not uniformly lit are not accurate. The user must insure that these conditions are met before utilizing per area units or make measurement corrections accordingly.
9.4
Typical Detector Signals The flexibility of the 1918-C Optical Meter analog signal flow is required in order that it may properly measure the signals that various types of detectors make. Basic optical power or energy measurements are related to a measured detector signal, S, in the following way:
P or E = Where:
S Rλ
Rλ = Detector responsivity at λ S = Detector signal
Semiconductor (918D/818 Series Low-Power) detectors provide a current signal. The 1918-C is capable of 10 pA resolution in order to provide the highest sensitivity performance with these detectors.
108
Principles of Operation
Thermopile (818P Series High-Power) detectors, provide a small voltage signal. The 1918-C is capable of 76.3 nV resolution in order to reach the sensitivity limits of thermopile detectors. Pyroelectric (818E Series Energy) detectors, deliver a peak voltage signal. The1918-C is capable of capturing 2 µsec rise time voltage spikes so that it may be operated with the fastest of these detectors.
9.5
Thermopile Detector Signals Thermopile detectors respond with a voltage signal that slowly changes in incident optical power. The time constant of most thermopile detectors is on the order of 1 to 10 seconds.
Figure 58
9.6
Thermopile Signals exhibit 1 to 10 second time constants.
Pulse Energy Detector Signals A Newport Energy detector will respond to a single radiant energy pulse with a voltage pulse at its BNC output. This pulse exhibits a sharp voltage rise to a peak followed by slower voltage decay that “undershoots” zero volts before settling back to zero volts. When a detector is operated within its proper limits, the voltage difference from immediately before the sharp rise to the peak is linearly proportional to the radiant energy. If a second pulse arrives before the “undershoot” rises back to zero volts, the voltage rise from this pulse will start from an initial negative value. At sufficient energy pulse repetition rates, a negative “baseline” voltage will develop from which the voltage rise must now be measured to achieve accurate energy readings. The 1918-C contains baseline capture circuitry that maintains its accuracy specifications over rep-rates ranging from single pulse to 10 kHz.
Principles of Operation
109
Figure 59 Typical Newport Energy Detector Signal Waveform An energy detector signal sharply rises to a peak value and then decays going somewhat negative before finally returning to zero. The energy in the radiant pulse is proportional to the height of the peak measured from immediately before the sharp rise.
Figure 60 Negative Baseline Voltage. Negative Baseline Voltage Due to a Pulse Train shown. If a laser pulse arrives before the previous Energy detector signal has fully decayed, the detector signal rises from the present decay point of the previous signal.
9.7
Peak-to-Peak (Photodiode) Detector Signals The 1918-C enables one to make peak-to-peak measurements of time varying signals from semiconductor photodiode detectors. Since optical power is a zero bounded positive quantity, signals from a detector observing such modulated light will similarly be zero bounded positive signals. To make a peak-to-peak measurement, the 1918-C must be able to capture both the maximum and minimum values of a detector signal. This is accomplished by sampling the signal.
110
Principles of Operation
Figure 61 Time Varying Signal Measurements. Many different measurements can be made on different portions of a time varying signal. The most common are: DC power, peak power, and peak-to-peak power.
9.8
Integration of Detector Signals The 1918-C provides for making measurements that integrate incoming power detector signals to obtain energy via the CW Integrate mode. In CW Integrate mode, the display units indicate Joules since energy is the time integral of power: t1
∫
E(λ) = P(λ)dt = t0
t1
∫
t0
S( t ) dt R (λ )
As the detector signal actually consists of a stream of digitized values, the integral becomes a numerical approximation using the trapezoid method. See Figure 62.
Figure 62 Integrated Energy Via a Trapezoid Approximation. The INTG measurement mode performs a discrete integration at a 400 Hz sample rate.
Principles of Operation
111
Two common applications are natural extensions of the CW Integrate measurement mode: 4. Pulse laser energy measurement using a thermopile detector 5. Energy from exposure over a period of time (dosage)
Figure 63 Measuring Laser Pulse Energy with a Thermopile. Thermopiles are often used to measure pulsed laser energy by integrating the response of the detector to the pulse.
9.9
Analog Output The 1918-C provides an analog output for signal monitoring. The analog output is the actual amplified detector signal and is uncorrected for the effects of the detector’s responsivity, calibration, and ZERO. The analog output signal is a representation of what the meter “sees” at its input. However, the analog output signal may be filtered if the user selects the 5Hz filter (see paragraph 4.2.5). Also, the analog output signal is amplified and scaled to the selected analog output level (see Table 5). The user can select the analog output level with a command, PM:.ANALOG:OUT (see Section 8.3). The analog output maximum level corresponds to the maximum full-scale input range the meter is set on. For example, if one selects the analog output level at 1 V, and the meter is set on 250 mW maximum full-scale input range, the analog output signal will have a transfer function of 250 mW/1 V. Therefore, if the analog output is connected to an oscilloscope or voltmeter and the user reads 0.125 V, the detector power is 125 mW. The selectable analog output levels are given in Table 5. Output Range
0
1
2
Full Scale Voltage (Load ≥ 1 MΩ)
1V
2V
5V
Table 5 Analog Output Range Table.
112
Principles of Operation
9.10
Measurement Considerations This section describes detector characteristics, optical and electrical considerations, and environmental influences on optical measurements. In general, measurement accuracy is limited by the accuracy of the detector calibration. Accurate measurements, however, are also dependent upon proper set-up, control of temperature and illumination conditions and understanding the factors that affect optical measurements.
9.10.1
Detector Calibration and Uncertainty Newport Corporation calibrates its detectors using secondary standards directly traceable to the United States National Institute of Science and Technology (NIST), to Great Britain’s National Physical Laboratory (NPL), or to National Research Council (NRC) of Canada. The details and uncertainty of the calibration procedure vary with each detector model but a detailed description of the calibration results is supplied with each individually calibrated detector. In general, detector calibration uncertainty varies from 1% to 8% and varies with wavelength. Each detector will also have some variation in response over its surface. Therefore, for the most reproducible measurements, light should illuminate the detector as uniformly as possible over as large an area as practical.
CAUTION Avoid focusing a light source onto the detector surface. Inaccurate readings and possible detector damage may result. Consult the detector manual for saturation or damage thresholds.
NIST trace ability requires that detectors be recalibrated on one-year intervals. As individual detector responses change with time, especially in the ultraviolet, recalibration is necessary to assure confidence in the uncertainty of the measurement. For the most reproducible measurements, the same detector should always be used for measurements that are to be directly compared.
9.10.2
Quantum Detector Temperature Effects Semiconductor (Newport Low-Power) detectors are affected by temperature. At long wavelengths, quantum detectors typically lose sensitivity with increasing temperature. Additionally, detector dark current increases exponentially with temperature. Observed dark current is often dominated by the interaction between the detector and a meter’s amplifier and is typically larger than the theoretical dark current limit. Silicon detectors are inherently quieter than germanium detectors due to their higher internal resistance and
Principles of Operation
113
lower capacitance. The noise or drift in the dark current sets a lower bound on the measurement resolution that can be achieved with any given detector. Cooling a detector significantly lowers its dark current and dark current noise. The observed dark currents can also be zeroed at any moment via the ZERO function. Since dark currents drift with temperature, the ZERO should be adjusted just prior to taking any measurements. If the detector temperature is constant, sensitivity changes and dark current drifts are significantly reduced. The 1918-C Optical Meter can measure the detector temperature and correct the power readings accordingly. The power correction happens automatically only for those detectors which are equipped with a thermistor (Newport offers detectors with thermistors for temperature compensation. See Newport web-site www.newport.com for more details.) The thermistor signal is read via the detector DB-15 connector and the displayed power is adjusted continuously depending on the detector temperature. The analog output signal shows the detector signal and is not corrected for temperature.
9.10.3
Thermopile Detector Temperature Effects Thermopile (Newport High-Power) detectors are significantly affected by temperature fluctuations arising from airflow disturbances. As the detector is a temperature-measuring device, airflow disturbances set a practical lower limit on the power that a detector can measure. In order to get the most out of any thermopile detector, be careful to shield the detector from airflow disturbances. Common sources of disturbance are: air conditioners and people walking past.
9.10.4
Energy Detector Temperature Effects Pyroelectric (Newport Energy) detectors are AC coupled devices and thus are not susceptible to temperature induced DC signal offsets or noise floor changes. One generally does not need to take much precaution with pyroelectric detectors except to make sure that their damage threshold is not exceeded.
9.10.5
Ambient and Stray Light Ambient and stray light striking the detector should be considered when making a measurement. Ambient light can be distinguished from dark current (or the detector/meter noise floor) by either turning off or blocking the source and covering the detector face with opaque material such as a piece of black rubber. Using the human hand to cover the detector is not advised because it emits a significant amount of infrared radiation and radiates a temperature significantly different from ambient. With the detector covered, a reading of the dark current may be made. Next, remove the material that is covering the detector and take another reading. The difference is the ambient light level.
114
Principles of Operation
NOTE Changes in ambient light levels can occur from such factors as turning room lights on or off, or by moving people or equipment. Remember, if you can see your detector element, then your detector can see the light bouncing off you. The effects of ambient light are greatly reduced when using a fiber-connectorized signal input to the detector. If free-space beam measurements are desired, using an attenuator will often improve the signal to ambient signal noise level. Wavelength-specific filters, such as optical cutoff, band pass, or spike filters can be used if the signal wavelength spectrum permits. Other techniques to reduce stray light include using apertures, placing the detector in a box or other housing to shield the surface from light (or air currents) and turning off room and other polluting light sources.
9.10.6
Signal Filtering The 1918-C Optical Meter offers the user the option to filter the detector signal. There are two programmable filters that can be used individually or together to condition the detector signal: the Analog Filter and the Digital Filter. The Analog Filter is a hardware based, programmable low-pass filer. The user can select the following settings: 5Hz, 1kHz, 12.5kHz, and 250kHz. This flexibility is offered to the user to improve the measurement precision for different detectors. It is well known that white noise has large spectrum. The noise level increases with bandwidth. The higher the noise, the higher the minimum signal that can be measured. The quality of the measurement can be linked to the signal-to-noise ratio (SNR): the higher the SNR, the better the measurement precision of very small signals. In order to increase the SNR the user may choose to cut the bandwidth of the power meter, depending on the detector signal. For example, if the detector is modulated with a sine wave of 800Hz, the user may choose to set the Analog filter to 1kHz to increase the SNR and be able to measure very small signals. Also, cutting the bandwidth at 1kHz does not affect the measurement. However, if the modulation frequency is 800Hz, but the signal is a square, the user may opt to cut the bandwidth higher, at 12.5kHz, to let the signal harmonics be unfiltered and minimize the distortion. Of course, in this case, the noise in the system will increase with the square root of the bandwidth. The user needs to asses the tradeoffs in his measurement, taking advantage of the 1918-C high flexibility in setting the proper filters for the measurement. Generally, the 5Hz filter is used for CW Cont. measurements. However, the 1918-C Optical Meter can measure the amplitude of AC signals down to 0.01Hz, so the 5Hz filter can be used for any modulating signal below 5Hz.
Principles of Operation
115
The Digital Filter is a moving average filter that can be set at 10, 100, 1000, or 10000 measurements. These values can be changed by the user. If the digital filter is set on 10, the average value is computed on 10 measurements, in a First In First Out (FIFO) fashion. The Digital Filter helps the SNR the same way as the Analog Filter does. With both filters on, low level, continuous signals can be measured with a high degree of accuracy. The Analog Filter is always applied to the entire amplifier chain of the meter. Therefore, the user will see the detector signal filtered at the Analog Output BNC. The Digital Filter is a digital signal-processing filter and is only applied to the calculated measured values that are displayed on the meter screen. While the displayed values may have both filters applied (An+Dg) the Analog Output can only have the Analog Filter applied to the signal. Because of that, the user may see a difference in the way the signal is filtered between the displayed values and the Analog Output values.
9.11
Common Measurement Errors The most common sources of optical measurement error are listed in Table 6 below. Other common errors are discussed in the preceding subsections of Measurement Considerations. Type of Error
What should be done?
Radiometry
Check that all of the light is actually hitting the detector
Ambient light
Check that any ambient light was ZEROed before the measurement was made.
Wavelength calibration
Check that the calibration factor for the measurement wavelength is properly set.
Detector saturation or damage
Check that the optical power density remains below the detector’s saturation or damage Table 6 Common Measurement Errors
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Principles of Operation
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10
Troubleshooting
10.1
Power Supply Problems Problem 1 The unit does not turn on when battery powered.
Solution 1. Use the external power supply to operate the unit and recharge the battery. 2. Verify that the USB-Host interface is not connected to a shorted cable or device. Verify that the battery is properly installed.
2 The unit does not turn on when powered from the external power supply. 3 The battery does not charge.
1. Verify that the external power supply is connected to AC power. 2. Verify that the external power supply connector is fully mated with the connector on the instrument. Check the PWR LED. 1. If it is blinking, verify that the unit is operating within the correct temperature range. If the battery is extremely discharged, the PWR LED may remain blinking for up to 30 minutes while the battery is “pre-charged.” 2. If it is not lit: 2.1. Verify that the external power supply is connected to AC power. 2.2. Verify that the external power supply connector is fully mated with the connector on the instrument. 2.3. Verify that the battery is properly installed. 3. If it is solid red, the battery is charging.
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Troubleshooting
Allow the unit to charge for at least three hours. 4. If it is solid green, the battery is fully charged. 4 Short battery life
1. Allow battery to fully charge. 2. Use the various power-saving modes of the instrument. 3. Disconnect any device(s) connected to the USB-Host interface connector.
10.2
Analog Output Problems
1
10.3
Problem
Solution
There is no AC signal at the analog output
Check if the 5 Hz Analog Filter is on.
Questions and Answers Q. I am trying to update the firmware but my USB flash drive is not working. I don’t see any light on the memory stick. A. The USB flash drive needs to be WinCE compatible. WinCE is the operating system of 1918C power meter. Q. Is the detector hot swappable? A. Yes, you can swap the detector without having to turn off the power meter. Q. Is it possible to write the measurement data into Spreadsheet? A. Yes, you can plug in a USB flash drive into the power meter and save the data from the Statistics screen. Q. Is it possible to use a third party detector with the 1918-C Optical Meter? A. It may be possible for some measurements by purchasing a special adaptor. Contact Newport Corporation for availability and details.
Troubleshooting
119
Q. I would like to change the configuration back to the factory default setting. How can I do that? A. Turn off the Power Meter. Hold down both “ZERO and “HOLD” buttons and turn on the Power Meter. A message window appears. Choose YES or NO for reset by using the left-right arrow keys and press enter. Q. The display shows some noise and fluctuation when I measure my CW light source. Any suggestions? A. Turn on the analog/digital filter. Check whether the meter and detector calibration is up-to-date. Q. Can I measure peak power or energy of a single pulse with a Newport low power detector (918D, etc.) and 1918-C? A. No. There is no energy or peak power mode measurement with the 1918-C when using a low power detector.
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Troubleshooting
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11
Maintenance and Service
CAUTION There are no user serviceable parts inside the 1918-C Optical Meter. Work performed by persons not authorized by Newport Corporation will void the warranty. Calibration accuracy is warranted for a period of 1 year. After 1 year, the unit should be returned to Newport Corporation for recalibration and NIST traceability re-certification.
11.1
Enclosure Cleaning WARNING Before cleaning the enclosure of the 1918-C Optical Meter, the external power supply must be disconnected from the unit.
The enclosure should only be cleaned with isopropyl alcohol or a mild soapy water solution applied to a damp lint-free cloth.
11.2
Battery Pack Replacement
Open cover to remove battery pack
Figure 64
Battery Replacement
122
Maintenance and Service
WARNING To reduce the risk of electric shock or damage to the instrument, turn the power switch off and disconnect the power cord before replacing a battery pack.
To replace a battery pack: 1. Disconnect the power cord from the instrument 2. Push the battery cover latches as the arrows show in Figure 64 and lift the battery cover. 3. Disconnect the battery pack from the instrument by detaching the connector from the contacts to which it is attached 4. Remove the old battery pack and replace with a new 1918-BAT battery pack, by attaching the connector to the contacts and placing the battery pack inside the compartment 5. Close the battery cover, while assuring that no wires are caught between the instrument and the back cover. 6. Reconnect the power cord, charge the new battery pack for at least 4 hours and turn on the instrument.
11.3
Spare Parts The following spare parts can be ordered directly from Newport Corporation.
Item
Newport Part Number
Equivalent
Battery
1918 - BAT
No equivalent. Use only Newport battery.
External Power Supply
1918 – PS
Cincon Electronics # TR36A2423A03
Power Cord
1918 – PSC
Qualtek Electronics #223021-01 or equivalent 8 ft max, SPT-2, 18 AWG, 7A, Nema 1-ISP to IEC 60320K7 cord.
Battery Compartment Cover
90000198
No equivalent.
Kickstand Assembly
45344-01
No equivalent.
Table 7 Spare Parts
Maintenance and Service
11.4
Obtaining Service The 1918-C Optical Meter contains no user serviceable parts. To obtain information regarding factory service, contact Newport Corporation or your Newport representative. Please have the following information available: 1. Instrument model number (on the rear panel). 2. Instrument serial number (on rear panel). 3. Description of the problem. If the instrument is to be returned to Newport Corporation, you will be given a Return Number, which you should reference in your shipping documents. Please fill out a copy of the service form, located on the following page, and have the information ready when contacting Newport Corporation. Return the completed service form with the instrument.
124
Maintenance and Service
11.5
Service Form Newport Corporation U.S.A. Office: 800-222-6440 FAX: 949/253-1479
Name _______________________________ Return Authorization #__________________ (Please obtain RA# prior to return of item) Company ________________________________________________________________________ (Please obtain RA # prior to return of item) Address ________________________________ ____________________Date _________________ Country _______________________ Phone Number ______________________________________ P.O. Number ___________________ FAX Number _______________________________________ Item(s) Being Returned: Model # _______________________ Serial # __________________________ Description _______________________________________________________________________
Reason for return of goods (please list any specific problems):
12
Appendix A – Syntax and Definitions
12.1
Definition of For convenience, the 1918-C recognizes double quoted, single quoted, and unquoted strings with certain restrictions as detailed below. Any of these forms may be used where a parameter is required. 1. ,using double quotes
“this is a string”
2. ,using single quotes.
‘this is a string’
3. ,using no quotes.
thisisastring
A description of each type of
